In Avenger's Endgame,
there is a gag about Cap's buttocks being "America's ass".
After the Cap-on-Cap battle in 2012 New York, past Cap is passed out on the floor, and future Cap (seeing his rear from third-person perspective for the first time) remarks, "It really is America's ass."
Given that there is a wide shot of both of them together, was this rear end played by Chris Evans' through compositing? Or was there a body double for this shot? Is the object of the discussion improved with either prosthetic or digital enhancement?