I was facetiming tonight on iPhone Xs Max running 12.1.2 I kept flipping around the orientation and all of the sudden the top portion of the screen has this bizarre message on it...referencing 1999? Super strange.
I'm officially embarrassed. You are completely right. It's the backside of my sister's cabinets - she had the phone propped up on the counter. Either way, you solved the mystery - thanks!