The picture of her in the red dress is on billboards. I agree, only a person with sharp eyes would recognize SW (as she was in more recent photos) from this photo.
The photo does, however, show the bone structure of her face, the exact shade of blue of her eyes, and how light blonde her hair is. It also clearly shows her teeth... So in those ways it is a good photo.
If SW is out there, disguised as a boy, the bone structure in her face and her sparkling blue eyes reveal she is really a girl.
The problem is, due to her age, she could lose teeth. I have a feeling she had a little growth spurt between this photo and going missing. But, i suppose most grown people realize a five-year-old can change in these ways.