Who knows....
I think with Prometheus a lot expected to see Egg, Face Huger, and Chest Buster etc... and so they was closely gaurding what they intended to show.
But Ridley never once said the movie was a direct prequel, he was vague and never gave away much but certainly never mentioned anything to directly suggest what we was in fore... apart from things like there is Alien movie connection (turned out to be Ships, Purpose, Experiments Black Goo etc) and he would have a Chest Buster rival Scene... and we would eventually see some DNA..... Deacon being the biggest.
This time we know that FINALLY we are going to get more concrete answers and we are going to see THEM ALL and so this time its not a surprise that we have Alien Eggs, and Face Huggers... as this is what was promised to a degree.... surely they cant make a movie and not give us those now after what he has said..
But this does not have to mean the Same Eggs... have to remember a Duck Egg, and Swan and Snake Eggs and Crocodile Eggs are all similar looking to a degree... but they lead to very different somewhat Organisms.
I find the comments so far and shots officially released have given a lot away, so much so that surely they are holding something back.... the Scene of Disaster Officially released shots would maybe be similar to if prior to Prometheus they released the Elder Engineer on set shots...
But i guess with this movie we know more about who they are, compared to Prior to Prometheus.
As far as those released photos of the Workshop... maybe yes they could be a decoy? How far a decoy? Was they planned concepts that then got the you know what, Nah we would leave them out... like few from Prometheus was.... then place this and take shots to lead us off the scent? Or are they purposely build props to hoax us... i doubt this though.
Even if they are real.... Fox would not maybe bring out Take Down Orders because sometimes this would then almost Guarantee there was something to hide... and may tell us they are legit....
But then once images are up on the internet, and popular and downloaded... they can keep re-appearing over and over.
But if they want to hoax us.... the best way is the double bluff... leak images of concepts that wont make it and then request them taken down.... this surely would get people to then expect they are going to appear.