These are the broccoli seeds sprouting. The seeds are the tiny dark-brown little balls. All the lighter colored bits are sprouts!
Now yesterday, when I initially dumped the seeds in (they had, prior to that, been soaking in a jar of water) it looked like there was a lot of water in there that hadn't drained, so I set each tray individually on a kitchen towel to soak up some of the excess. Last night, when I did my rinse, I didn't do that. I think that way leaves too much water in the seeds. Again this morning when I did my rinse (after I took these pictures) I set the tray on a kitchen towel momentarily to wick away some of the excess water. I don't know if I'm *supposed* to do that or not, but the guy giving the lecture had said that excess water was not good. He was speaking specifically about water left in the bottom tray after rinsing, but I'm choosing to extrapolate. More research may be needed.