Yep, looks about right. You just want the top of the bubbles to slowly roll over the side fo the cup. Not too much or you're emptying the cup constantly and not too little and not skimming anything. As you skimmer gets broken in, it will create a larger head (bubbles) and more efficiently skim. The color will get a lot darker and it will take more waste and less water.
I'm emptying my skimmers about once every week(ish) but that can vary with different people and skimmers depending on how tuned in you want it.