User blog comment:MalaCassida/Ozpin is possibly in the V4 intro?/@comment-4010415-20161028135537

I'm actually fairly sure that's Qrow's leg. It looks different from his leg because it's the back of his leg, and the sunlight is coming from behind him, so the lighting makes the back of his pants leg lighter than the front. I got a couple screenshots. Qrow is watching RNJR, and it transitions to show Qrow from the front instead of from his leg.