And more importantly, see how your eyes and face move. Especially with a silent film. Granted, a lot of it was broad physical comedy because it had to be. Arbuckle was amazingly agile for his bulk and an extremely talented physical actor. But he also relied a lot on his comic facial expressions. Keaton did not, drawing much of his comedy mainly from his having no expressions which is I guess why he is pretty much plain pancake looking like Mark Zuckerberg whereas Arbuckles make up is designed to show all of his expressions .

Arbuckle was quite charismatic looking and had very nice eyes and if I'm remembering right, would be able to draw great comedy out of using his eyes like the female film stars of the era, fluttering and other typically feminine use