u/bitsbybones

I've had this framed print in my bathroom for about a year now, and I've just now noticed this bizarre, egg shaped...haze? Something? In the center of it. It looks like fog...but I don't see how that's possible, AND it's this perfectly symmetrical egg shape. I'm also not sure if it was there the entire time or not! Nothing is wet. The back is totally sealed. I am stumped.