Hold on, looking back at this short and sweet comic, I come to two conclusions...
1. Pico is now in shock of his arm being snapped, due to immense pain/PTSD or ...
2. This is something that Pico goes through once in a while, as his face may also say, "Oh boy, I've been through this before", which isn't surprising, as the dude literally went through a certain school massacre when he was young.