Personally, I think there's nothing wrong with using photos at all. But, only for practice and understanding how everything works. CalArts wants the real deal, how you apply your understandings and thoughts down into paper, and provide a unique voice in your content through figure drawing and studies from real life.
Reason why drawing from real life is more important than a photo is because you can move around the figure and look at them as a three dimensional model. It'll be easier for you to imagine them as a living being, rather than a two dimensional photo where you are stuck in point of view, one perspective.
If you draw based on photos, it'll seem like you're drawing shapes with shading on top, making most of them look flat. If you are an expert in form, then I would say have a blast with photos or real life, but I don't think any one of us, yes, including Sunny Delight, is an expert in anything quite yet.
