It looks heavily edited, based on her top being nearly as pale as she is when it almost certainly shouldn't be, and the fact that I’m very likely the same color.

The good news is if you are that pale, laying in the sun -being an activity you don't do often- is actually pretty uncomfortable. And doing nothing else while laying in the discomfort doesnt last long because how boring (unless you fall asleep I suppose). If you are the sort who can just do sunbathing, you probably aren't the sort to be casper white.

It looks to me like she's actually covered in sand? The bottoms of her feet aren't as white.