Bad choice of words (well, I did put it in quote marks).

How about "such bubbles would have more EM energy going into them than going out, if you count each photon crossing the boundary only once."

Of course, it's trivially true that, absent absorption inside a sphere, any sphere will be a net 'emitter' so long as it contains a souce anywhere inside it (all photons entering 'from outside' will also exit, absent absoption).

But this is an aspect of the OP's idea that I think we need to have him clarify, before we can consider it further, don't you agree?