The entire point is that there's obvious image composition and layering; that's why some parts of the picture are not affected.
There is something
going on in the video, yes, but referring to "layers" (a term from digital image editing) rather than something else is at least implicitly assigning a specific cause, and you say "parts of the picture are not affected" as if that is proof this is a layered video based on a green screen. This effect doesn't need to come from digital editing layers.
Images are compressed with several techniques. One technique is that each frame is not stored as a stand-alone image. Instead, because most of a frame in a video doesn't change much, the difference between frames is stored in some way. Much modern video compression uses motion vectors, which means a block of pixels (dots in the image) is assigned a small motion to describe how that block of pixels translates for the subsequent frame. For example, a 4x4 block of pixels at locations (20-23,32-35) might be associated with a motion vector of (2,1), indicating that the block should move 2 pixels right and one pixel down for the next frame, and fill positions (22-25,33-36). This works great for compression because most of the image doesn't move at all, and the parts that do move tend to move in blocks in the same direction.
If the motion vectors were repeatedly applied without new info, the pixels in the same 4x4 block (20-23,32-35) would again be moved in the (2,1) direction to (22-25, 33-36). Whatever pixels were in (20-21, 32) would be duplicated, but they would never go beyond (25, 36). They wouldn't affect the entire image, only as far as the motion vector goes.
There may be other reasons to think ISS feeds are green screened, but I just don't see the evidence here.