That looks much better. Proportions look good. Butter is absolutely correct, not chemically modified vegetable oil, suitable only for refilling sumps or greasing rails. I mean, margarine.
Leave LOTS of room on the tray, more than you think. They spread a lot. Although, it is ok to let them run into each other a bit. They break off fine, and the edges don't crisp.
Slightly underdone is how I always do it, too. Just getting brown on the bottom. Then hot out of the oven, all droopy and soft, mouth scalding and an icy glass of milk.
Sigh.