My intuition is that these will be a hit. Simple, fun, youthful & on trend, not fussy to charge, huge captive userbase to sell to. Can you turn them around and use the mirrored lenses to take a selfie?
Snap probably has a winner here if their users will further embrace the idea of turning cameras away from their faces and onto their friends and experiences. How big an "if" that is, I can't yet say.
I think they're too trendy looking. They'll be fine for a season/uni semester, but after that will drop out of fashion. And they'll be too pricey for their core demographic to keep buying new ones.
I can't help but feel they are signalling their intent to be an eye into my private life, not unlike the monitoring predicted in 1984.