Wish I could look at a 4 week old tomato plant & tell what it needed to be healthy.
I've heard people say they let the tomato plant tell them what it needed, but mine won't tell me anything.
I think it's okay too @hdan. Tomatoes do weird things sometimes, I've even seen this on fully grown potted tomato plants occasionally. Sometimes leaf curl is a problem, but not always. And sometimes once planted outside it looks totally normal again. When you transplant you can always strip off those bottom leaves and sink it deeper.