Could have been something frivolous to rock red socks at the time so the dude wanted to stay anon. But the painter liked to have that mysterious red socks guy as motive. I read some homo erotica into that.

If I had big calves, I'd the same thing

Honestly might be what they're going for here. Idk when this picture is from, but during Chaucer's time, "well-turned calves" were all the rage.

Thot in loafers -oil on canvas