aside from the mauling of a good painting and excesive use of leet, i don't get the point.
umm... well, it's a ply on words...
Light brigade > l33t br1g4d3
And they're speaking l33t... because they're the l33t br1g4d3... who speak l33t... because the battle could be made into some kind of Online game... never mind.
Oh, and don't worry about the painting being mauled, I'm sure they made a copy of the original to put back up in the gallery before adding the speech bubbles.