It's actually a command which you're writing in console. I think I saw it in his video about how he does his animations.

yeah i saw the one about the r_eyesize or something like that but i want to know how to make the physical eyes bulge out of their sockets instead of just the texture

it could just be the way he uses the faceposer

I think you go into bone editor and stretch the eyes out maybe

no it's r_eyesize

he talked about it in his tutorial.
he said r_eyesize 0.3 was the one he normally does

I used another models, like enhanced spy or something.
Those models had bones for eyes and brows
That was the only time I used models like this