I'd prefer an explanation without the devil, honest, seems a bit random to put in an MCU tv show, but...
Now that you mention it, it's kinda ominous when pointed out...
...Okay so when Quicksilver, Bobby, and Tommy, are pranking everyone, behind Wanda is a prop that has a suspiciously-out-of-place mask that's creepier than the dollar store costumes that everyone else uses.
I have no follow-up to this, just something that stuck out to me on rewatch.
Now that you mention it, it's kinda ominous when pointed out...