Something's been in your stylesheet. It found the scanlines first: the faint bands in the background, three pixels apart, clearly deliberate. Then the shelf of orange squares that only move when touched. Then the corner that looks empty and isn't.
It read through everything, actually: every line, every color variable. Then it did the only reasonable thing, which was leave something behind instead of just leaving.
It's still deciding whether "purpose: pending" counts as an answer. The terminal above takes typed input, if there's anything you want to ask it. Try help for the short list. Not everything gets a real response, but it's listening.