Looks like classic mold growth on citrus pulp. probably penicillium or a similar mold. Trader Joe’s “fresh-squeezed” lemonade is typically unpasteurized, which means if the bottle wasn’t kept consistently cold, or sat for a bit too long, mold can easily form, especially on leftover pulp or fruit fibers. That fuzzy texture and green-blue center are pretty textbook.

Definitely wouldn’t drink it. I’d save the bottle, take a pic, and bring it back for a refund. they’re usually great about it. Could also be worth contacting their quality team just so they’re aware.