These pics look good, and it appears there might be some lactic activity going on in the starter. You could add a little maltodextrine maybe to feed the bugs. When are you planning to add them to a beer? I have found that JP dregs are pretty active, and within 3 weeks of adding them to a p-Lambic, it formed a nice pellicle. That was nearly a year ago, and the pellicle has fallen and reformed!