Hmm…tricky question, but fun to think about!
Specific phone models, I can’t be 100% sure, but what I do suspect is that Mal has an old phone, cause he’s not really…with the times. Jeremy, Amy, Kai and maybe Natara would have updated phones though. As for Blaise…I’m not too sure!
As for the actual pics and vids…
Mal - probably not too many, unless they’re of Natara sleeping
and you know she made him delete them right away
Natara - couple-y pics, maybe some scenery and evidence.
Jeremy - you know he still has that duckface pic…you just know it
Amy - Everything. I’ve always imagined her as the documentary one, since she’s into tech-y stuff! Pictures and videos of every occasion!
Kai - selfies, endless selfies…and stalker pics of his friends when they aren’t looking
Blaise - Probably a few selfies, evidence..idk!
these are all complete guesses I feel like they’re not even accurate… feel free to add or correct me!