Longtime Genova's Witnesses will be familiar with the ever present entity that is "The Claw." A possibly benign, probably malignant entity that manifests itself when Genova is put under pressure and his brain loses control of his extremities. In his earlier videos it wasn't as noticeable, but as Jason has grown in power, yet seemingly diminished in mental capacity the claw has risen to exert even more of an influence.
There are Genova's Witnesses who maintain that Genova is actually the malignant entity, an evil potato who has taken control of the Crab Lord, and that at heart Genova is actually a crab, not a potato. There is .gif footage of a young crab that looks suspiciously like Genova, giving credence to their theories that Genova is in actual fact a crab and not a potato at all, and that the potato side of him is a fucking scam artist.
The claw/crab manifests itself when Jason is feeling tired, under stress, is lying, can't chew on his t-shirt, play with his hat, or formulate a coherent sentence.
The claw thwarting Jason once again, notice the strain on his potato as he struggles to keep it under control.
The claw can be anything from a thumb and baby finger on his left hand alone to both hands working in unison as dual pincers. Depending on how much cognitive function the potato side of the brain is using to conjure up a lie, you can see how much freedom the claw has to operate when the potato brain is occupied elsewhere.
The claw fully in control of both hands and facial features for a brief moment, we can assume it was driven out after it took control of Jason's sense of smell and caught a whiff of the ripe odour that Jason likes to cultivate.