QR codes are a huge problem in contexts like this, because they are easy to overwrite and impossible for a human to verify the legitimacy of.
This means anyone with a sticker printer could slap a malicious QR code over the genuine one, and you won't know until you've already scanned it. This could easily take you to a clone of the restaurant's website for example, that instead steals your passwords or bank details.
I completely disagree that it is not using anything that identifies the universe. The visual language of Star Wars is very strong, and even besides the obvious storm troopers this show captured it in its' production design in a way that very few recent introductions have.
I would argue that almost any frame could be immediately identified as star wars even if you hadn't seen the show.