DAMN Sap, that clone in the middle pic is gonna have a fatty stalk on her.
The rooting on top might be from the rooting hormone oozing out from around the stalk and out of the hole..that's happened to me before I used to use oasis cubes in the propagation tray w/ dome. I just recently built a bubble cloner like yours but w/ the neoprene collars...cut em, dip em, drop in the cloner, then transplant to net pots and start em vegging after their root system has developed..so much cheaper then buying a cloner retail.

D:S5: