To say something is abstract is a little bit subjective. We all see things differently and the idea of abstract art is that something is removed from its natural context to a degree that it starts to communicate in a...what...am...I...saying?
These images are simply about pattern. In some cases it may be quite clear to you what you're looking at, but they're in this Abstract section because of the overall effect of the full photo, rather than because it's a photo of a specific subject.
Does that make sense? Feel free to use the Contact Us form to let me know.