Yes, I guess it depends on what "picture" covers legally. Is a bijectively transformed version of your picture the same "picture"? How about a degraded version? How about a 3D model of your face?
Exactly. "We don't store your picture, we store an abstracted entity that allows us to recognize your picture in the future." The latter part is what people are concerned about anyway - the abstracted representation of "their face", not some particular photograph.