>>89204941I don't think they look like Nijis. I think Regloss does, and Advent has just a hint of it. Someone looks like a Niji to me when they edge more towards realism: more adult proportions, muted colors, mundane outfit (or outfit that matches the rest of their gen), lore is probably just that they're a high schooler or something simple like that. That's what I think of when I think of Nijisanji. Hololive is the opposite. They tend to be more cartoony with brighter colors and more childish proportions, they're often fantastical - either kemonomimi, fiends or having something like an RPG class, etc. That doesn't describe everyone, of course, there's overlap - there are Nijis that are brightly colored wizards and there are Holos that are just plain-looking school girls - but that's not the norm.
Laplus said it herself: there was an obvious attempt to use Regloss to appeal to a non-Holo audience, probably Nijisanji, because Cover doesn't benefit from appealing to pre-existing customers, they want more customers, which means new customers, which means doing something new. And this pans out when you look at their designs: they have just a little bit of mundane lore, muted colors and one or two are basically designed to look like dudes. This is why Nijisanji's more successful with female fans and Hololive's more successful with male fans to begin with. Men like novelty and individualism and they like their girls to be cute and colorful and that's what you see in Hololive, while women are more down-to-earth and like collectivism and a more complex, nuanced use of color.
To me, Flow Glow doesn't look like Nijis (maybe Niko does), but I'm not as familiar with other agencies to say what exactly they look like, just that they remind me of other vtubers I've seen. Just off the top of my head, Chihaya very obviously looks like several VSPO members, Riona and Vivi remind me more of the Vshojo/Twitch crowd, and Su reminds me of some of the girls from smaller agencies whose names escape me - maybe PRISM or something.