I guess it could be done but it would be very time consuming.
It was done for the flights/mounts etc as you cannot preview those in game without buying them,
however you can preview skins, even if you have to jump on a different character.
It takes you a couple mins to switch characters, but would take several days or longer to compile something like this,
given how many different skins are in the game.
I remember it take Magestic a very long time to do the Boutique Forge guide.
If it is something that is badly wanted by people, then I will happily do it, just saying why it hasn't already been done.