They are/were rolling air cells. This one is sloshing.
Can a saddle air cell (which I had NOT seen one day one) look like sloshing? That is the only other explanation. It really looked like sloshing though..
sloshing kinda looks like waves on a beach and foamy bubbles included. The air cell is probably ruptured. check this one for weeping everyday. Keep it upright. Does not look anything like a Saddle cell.