from the years growing tomatoes, first time i've seen something like this, but this is the first time i grow this variety (Steak Sandwich) which is probably some big beef tomato..
two on the left are growing the same way, the true leaves look a bit anemic and slightly pale green. the plant on the right is super sweet 100 and looks perfectly "normal" from what i'm used to seeing. both seedling have the same mixture of soil. it's almost as if the ones on the left are showing some deficiency which i don't see how that's possible when they're only 2 weeks old.

the only thing i can think of is the soil ph is a bit lower than i wanted due to running out of soil and adding a bit more peat to the mixture, around 5.5, but from what i gather tomatoes don't usually mind soil a little on the acidic side. the one on the right certainly doesn't mind.. whatcha think, or is this the variety trait?

(high resolution warning) pic: http://i.imgur.com/lZfCTxs.jpg