what does the phrase "all rights reserved" mean?

Looking for the meaning of the Phrase all rights reserved.

I want to refer to someone's photography.. and jokingly insert a legal phrase in there.

When .. so and so posts, I expect to see his photographs (legal phrase denoting his 'ownership of' here).

it does not have to be official, I am doing it more on a play of an issue he had with copyright infringement after posting pics to a public forum.

Thanks so much in advance.