Is David transmitting a signal that only Walter can hear?

Nah. I think the simple answer is it is David. It's plausible that David is impersonating Walter, but that would be a tired plot trope. Having said that, if it is indeed David then that in itself is the tired plot trope of a 'honey trap'. Thank Yaldabaoth I'm not a screenwriter!

I think David could communicate in a way the crew would not detect but Walter could..

The clothing matches Walter, it could be David in dissguise this would have to mean we would have to wonder when did David change clothes, hair etc or how does he do a Mind Swap?

We need to look at the time frame and which frame of time could this happen... we need to remember events in the trailer may not be in the right order and time-frame from one scene to another may not be as close as trailer hints.

The New Trailer however holds some clues...

Clearly David/Walter leads Crudups Character down some steps and into this room..  thus the Walter/David must have some knowledge of what would be down there.

Uli Latukefu is latter shown coming down the same steps before a Face Hugger tries to get to him....

Another Scene Uli Latukefu is in the Laboratory Room looking at a Body on a Table and the Xenomorph attacks... i think it is more likely he survived the the Face Hugger and ran off and ended up in this Room... where the Xeno came for him.

The Question is Time-frame...

I think it looks like Latukefu is with Crudup when he tries to run back to the Ship... but it could be Daniels with Crudup Character.

If it is Uli Latukefu with Crudup then after this they head off to the others and this would sugest they remain close to each other... which would add to maybe Latukefu comes down after Crudup is Face Hugged and then a Face Hugger goes for him.

HOWEVER...

What if the Person on that Table is Crudup... and some time had past and David/Walter removed the Chest Buster, and  Latukefu latter went down to the Egg Cave then ran off and headed to this room where he is killed by the Xenomorph

The Question is where did this Xenomorph come from as they need Hosts.... if its from Crudup then some time would have to pass to get to a Adult Xeno... unless these can grow at a faster rate?

Is the other Chest Buster Scene Crudup? If so then this would rule out him being on the Table... unless David/Walter find the Chest Busted Body and then wish to perform a Autopsy

I agree. 

Why send one android into the cosmos when you own the factory that builds the androids?

What if the common denominator for all David models was to pursue the objectives of the multi-decade Prometheus Project?

David 8 would not have to transmit anything if he and Walter were on the same page from birth.

I suppose weyland wants to know what happened to the expensive ship and crew that went on prometheus, covenant could be to terminate shaw and david.

maybe its like aliens, weyland know there are engineers and other goodies out there, the david droids simply follow orders to learn it and where possible, obtain it. If david has spent 10 years experimenting he is a valuable asset, let him do more!

I agree. I'm sure Weyland Industries wanted to know where the more than $1 trillion was spent on the mission to LV-223 Babylonxeno.

ninXeno426 and Centauri, I saw your conclusion here in regards the Walter androids potentially housing DNA from a customer (or Peter Weyland..I was thinking the same thing) and are there any "customers" on the Covenant crew. Great discussion and conclusions.

Taking that into consideration, would it not be a stretch with the "We are Walter" ad campaign that the Walter model was built to share the collective "knowledge" of the entire Walter population with each other?

With that to consider, then the pieces would be in place for David 8 on Paradise to communicate with Walter and they (David and Walter) could give the Covenant crew updates on their plans (below) whenever they wanted or not at all.

New media coverage:

"So far, the clips all showed beats familiar to fans of the long-running scifi horror series, however, the third one harbored the most morbid twist. In it, we saw Captain Oram talking to an android played by Michael Fassbender. However, this wasn’t the newly revealed Walter model. It’s David, the android last seen in Prometheus, who explained to Oram that he’s become something of an amateur zoologist. As the camera lingered on dissected specimens, David revealed he’s been studying the xenomorph. He explained that he’s mapped how insectoid carriers burst from spores to infect hosts and create hybrid lifeforms. Davis spoke admirably about the adaptive qualities of the xenon as he led Oram to a subterranean chamber filled with the iconic Alien egg sacs. Oram asked about the status of these sacs and David replied that they’re “waiting for mother” and assuring the human they’re “perfectly safe, I assure you.” The flaps of one sac opened, showing motion behind a cloudy membrane. Oram leaned over the opening to peer inside and a face-hugger leapt onto his head. David watched impassively as Oram struggled and died."

http://io9.gizmodo.com/we-ve-seen-at-least-one-very-grim-secret-at-the-heart-o-1793188750

A trailer for this topic has been uploaded to YouTube. 

Thank you all contributors.

https://www.youtube.com/channel/UCwyNYNcR59pbLUGn4_qhx8Q

KanesSonDoesDallas made an excellent point here in regards to wrote or produced Special Order 937.

With Special Order 937 (as Priority One) in place, that would negate the need for David 8 to transmit a secret signal that Walter could hear and the Covenant crew could not. 

Walter would show up and be on the same page with David 8 without any conversation. 

They would be like two peas in a pod.

I'm new to this forum, just found it recently, so if this has already been discussed please post a link to the original thread so I can check it out. Thanks

Has this David/Walter funko been discussed yet? 

I've seen people point out that they messed up the name and is supposed to be Walter. I've also seen a couple people use this as evidence for the theory that David does try to impersonate Walter and deceive the crew. Any thoughts about this? 

ObscureMammal, that is crazy.

No, I hadn't seen that yet. What a find of significance in relation to the topic of David 8 and Walter and if David 8 was able to pass off as Walter with the Covenant crew. 

Thank you.

page 344 of the novelization with David 8 talking to Mother..."Use hailing code David 31822-B".

Atypical Energy Burst that Crippled the Covenant

There is no daylight in-between Mother and David 8. page 26 of the novelization "Sector 106. Very close. Source was masked, hence the unusual-no, extreme proximity prior to discovery."