The soil does look low, and a bigger pot will definitely be better. You'd be surprised and find that your babies tend to grow faster and get pot bound sooner that you think! Also depends what soil you are using. I use a mix of ffof and happy frog which I don't feed until three to four weeks into veggin. They grow nice and big without the nutes. It is easier to add a bit of nutes if your babie shows signs of deficiency than it is to over nute and burn them. I know some people that, depending on the soil they use, they don't use nutes at all for vegging, heck they dont even own veg nutes, all they use is flower nutes. I agree stay off nutes for at least one week, preferably two, if your soil is heavy in nutes like ffof. Transplant to atleast a true 5 gallon, better yet a 7 or 10, or bigger the better.