Looks like someone got in the way of an energy blast. The bulk of it melted the arm completely, while the outer part was enough to melt the arti-skin (And the silicon breast filling).
Hopefully there’s a replacement arm available where she is Otherwise she may be a bit less dexterous for a while.
In this piece, beyond sketching out this idea I had I tried using a “hair brush” for the hair, instead of my regular style. I like the result, though I need more practice with this method.