Putting a cheap piece of paper or vinyl with glue on the back on top of a nicely-finished guitar seems impulsive and backwards to me. Unless the finish is poly, finish damage is not inevitable but very possible. The sticker blocks sunlight, often leaving a darker area underneath if you remove it. Stickers for branded, non-musical products seem idiotic to me, thought "cult" identifiers -- such as Harley-Davidson -- are by now customary enough to be a "thing" (or a meme?). If you really want opinions, mine is that those particular stickers look like s---. Color, shape, content... in all respects, I think they're just an eyesore. They remind me of PGA shirts with little logos embroidered for cash, or a NASCAR paint job with advertising everywhere.