They aren't Cornish Rocks that's for sure. Those are all white.
Perhaps they are red or black broilers? I would find out from the TSC you got them from, which hatchery they ordered from. Then you can track down their website and see what type of meat birds they sell...
They're not to bad but then again I don't usually handle the meat birds very much, just so I don't get attached. I know my TSC ordered their assorted pullets from Ideal.
So far I haven't found any that look like them. Mine are almost 3 weeks old I think and I can't find any pics of any around that age. Its just that they are growing soo much slower then the cornish that I have. The bin siad meat birds and I asked the lady what kind they were because I saw there were a bunch of the little black and white ones and she just said they were cornish. I have not had any cornish that look like that before. My cornish that are the same age as those little ones are already huge compared to these.