i'm praying that's a really old screenshot... otherwise these guy would be melting right now... (although they can melt AFTER i get my badge from them..)
Old indeed... that shot was taken in December 2004.
As for the snowballs reference, it was the first temporary power I got outside of a mission, given during tha same winter to all characters. It came along with the Winterlord - ergo the reference. It was, in the game, the very first time you could attack another player (although without any damage)and the only way you could look like you were physically interacting with one (the slap or smack emotes were not even available then). The arenas themselves weren't built at that time.
It was reinstalled temporarily during last winter, but not the Winterlord himself (alas for powerlevelers).
