Most likely "old man skin", but why not hypothesize?Why risk having a mask fall off (or produce unsightly and embarrassing wrinkles) when you have an armada of clones? It does appear that there are at least a few body doubles for Biden, but the doppelgangers almost always get noticed. It would be easier to make somebody that already looks like Biden, look like Biden. I am going with "Biden body double in a Biden bodysuit".