Someone who bought and expected to make a profit, but reached a point where they hit their stop loss or just wanted to get out the trade at any cost and couldn’t bear to wait longer. Quite possible a redditor who frequents r/wallstreetbets and YOLOed in.

They're not really making any money when they close out their short position. The money came when they first opened the short position and sold the shares. When they close they just lock in how much they're going to net off the position.