word usage - "Photos of Someone" vs "Someone's Photos"

In facebook, in the photos page, you will see:

I know the difference in facebook, the first tag "Photos of Someone" will show photos you are tagged in, the other tag "Someone's Photos" will show the photos you uploaded.

Is there a difference in English between "Someone's Photos" and "Photos of Someone"? or was facebook out of words so they just used this?

Answer

In general in English, "X of Y" and "Y's X" mean the same thing. If I say "There is Bob's office" or "There is the office of Bob", there's no difference. Either way it means that X is related to Y in some way. We often speak of it as the "possessive" and say that it means that Y owns X, but we mean that in the broadest sense. If I say "Those are Sally's shoes", I probably mean that Sally owns those shoes. But if I say, "That is Sally's office", I probably don't mean that she literally owns the office, but rather that it is the office that her employer has designated for her to work in. And if I say "Britain is Sally's home country", I surely do not mean that Sally owns the entire nation of Britain.

So when you think about the possible relationships between a person and a photograph, the most likely are that the person owns the photograph, the person is the photographer who took the photograph, or the person is the subject of the photograph. (There could be other relationships, but these are the most common.) If we say, "That is Sally's picture" it could mean any of these. Technically, grammatically, if you say "That is a picture of Sally" it could mean any of these also. But in practice, we usually reserve "picture of Sally" to mean that Sally is the subject of the picture. "Sally's picture" is much more ambiguous. If I heard the phrase without any context, I think I'd most likely assume that you mean that Sally was the photographer or that she owns the picture, but it could be used to mean that she is the subject.

Note that there is nothing peculiar about pictures here. The same ambiguity exists for many uses of the possessive. If someone said, "That is Bob's house", he might mean that Bob owns the house, or that Bob is renting it but someone else owns it, or that Bob is the construction contractor who built it, etc.