the post-match accolade cards do show your skin and any applicable mythic customizations but not your weapon variants. [yet?]
for sigma, his animation is specifically the classic hero select animation. which is at least 3x nicer than OW2's hero select animation.
his melody plays on this screen; it seems to be more noticeable and more loud than anyone else's load in noises, which is nice, because it's a melody.
this animation was never shown on his mythic during the classic rerun events because his mythic hero select animation would override as priority even then.
if chosen as MVP, he uses the applause emote.