it's the three legged stool and both the two front legs of the stool are behind the little brazier heading the tools. The steam is obscuring the spot where the front right stool leg intersects visually with the brazier rim so it makes it seem like the front right leg is closer to the viewer than it is.

Guessing those are the soldering irons and were rotated through so there's always one hot enough to melt the solder used to hold the pieces together.

Edit: if you mean the chair legs, two of them are actually human legs and the other three are a close one lit by the fire, a far one shadowed by the seat, and the middle distanced one which has questionable lighting at best.

Gotta love them 1930s-50s historical recreations, where everyone just styles 1930s-50s hair and (lack of) beard styles. The one closest to us even seems to be using some Dapper Dan in his slicked back hair.