Well first and foremost we can start with High Definition textures. These will take up more RAM for the game to process visually along with character models etc. The amount of objects (player characters, NPC, terrain objects, decorations, etc.) in any given area could be limited by the low amount of RAM available in the PS3 as SE wants everyone to have an equal experience when playing the game. The amount of items available to be visible on a character model would be limited by the small amount of RAM, character creation options which if more options were added would cause each character to take up more RAM, just anything that you can think of that’s going to take memory for the game to display is going to be limited by the 512MB of RAM available in the PS3.
Again, with SE wanting everyone to have the same, or nearly the same, experience while playing the game, SE will not add things that people with more RAM can benefit from to the point that it gives a PC or PS4 player an advantage or a much better gameplay experience compared to a PS3 player.
While I am sure there are some limitations for the game due to the aging of the PS3’s hardware 90% of the limitations people are claiming are simply due to poor optimization or coding, or a lack of willingness on SE’s part to actually impliment something. Those clamoring for high resolution textures but say they wont make them because of ps3 for example I would like to question how you think they make them to begin with. Most every artist starts with an ultra high resolution creation then it is downscaled to be put in engine. The reason the PC doesnt get these is because SE has not and probably will not release them. A lot of the “PS3 limitations” for features that people like to blame are often back end coding implimentations that run server side so blame poor server hardware and coding for most issues. There are some limitations the PS3 cant overcome, it does indeed have limited RAM that is shared between video and system memory but that is where things like draw distance low poly models view fogging and the like can be implimented. Most people want to blame the console but really they should be blaming the programmers lazy spaghetti code and poorly optimized server architecture.
as a person who went PS3 to PS4, I can state there are a few things that are diff between both versions: Resolution detail (Texture & draw distance), number of players visable at once (good luck making to a Zerged hunt & seeing it on PS3), speed of information loading (also affecting previous example with Hunts), Effects & slight animations (the shine from gather nodes is dimmer on PS3, also “Jiggle-physics” aren’t used on PS3 but are on PS4 then there the shine effect they added to floors in 3.3 that PS3 can’t have)
I doubt the PS3 is acutually “Holding us back” like said (as the game is only slightly diferent between PS3 & PS4 but its still playable on PS3 (u just miss out on “Fluff” effects is all) I thinks its more SE & Dev’s atempts to keep the only diff being these “fluff” effects (look at the diff between DA: Inquision, PS4 just has more background NPC’s & stuff when it ant a cutscene both are playable just 1 “looks” cooler due to having more “Fluff” is all))