Since the Ryder children are twins, I assume you can't customize them too look wildly different, like a black male Ryder and a white female Ryder. I'm assuming the things you can customize on the Ryder you are not playing will be like hairstyle, hair color, eye color and small things like that. Doesn't matter though, I will still end up spending hours customizing a character that I won't even get to play, but that's part of the fun.
And I'm really loving the backstory for the Ryder family. All this family stuff reminds me a bit of Hawke from DA2, which some might not like, but I always felt that it made Hawke a much more compelling character then the generic, blank slate character from Inquisition. It will hopefully lend to more more opportunities for roleplaying moments in Andromeda as opposed to Inquisition, where I always felt the Inquisitor was the same, regardless of what you did and said.
Also, Bioware better bring back the cinematic camera. You could make an excuse for Inquisition, where you had to take the protagonists height and race into consideration, but this time, you're playing as a human, so please bring it back Bioware. When I'm spending hours customizing my character, I would like to actually get a proper look at it in conversations, instead of seeing him/her from a distance. Don't let me down on this, please.