When roots will grow, you will not be able to pull it out without damaging the plant or the roots and will have to cut the lid. Smaller glass and problem solved.
Did you know there is dissolved oxygen in almost all water. Especially when she sprayed water into the cup creating surface agitation. The plants won't be in long enough to warrant an air bubbler like in a hydroponic operation, and since you add water the little surface agitation will suffice for the trace amount of dissolved oxygen required by a plant with absolutely no roots to little roots.
