They used vectors, looks like the Windows 95 aesthetics that was so connected to pixel survives this transition quite well!
That seems more like retro/throwback fashion (which is always a thing, in every era) than the fundamental principles of that aesthetic being incorporated into modern design (which is what I would typically consider actually being "in fashion").
Still, nice to consider we're at the point where that's what we're framing as retro. No longer is it System 1 or CRT terminals.
It's certainly big in vaporwave and, to some extent, synthwave. Obviously both genres of music but also, and particularly the former, very strong aesthetics.
Then again, I was a Memphis beta tester (legitimately, not the "I found these rars on a warez site" variety of "beta tester") So I "enjoyed" some of those features pretty early on.
Haiku has this delightful vibe to it, I can't explain.