Examples should be there to represent abstract. I repeat: picasso and van gogh are not abstract. That's why I asked.
Abstraction indicates a departure from reality in depiction of imagery in art. This departure from accurate representation can be slight, partial, or complete.
...but they are?
The whole point of having those examples in OP was to note that abstract art is very broad and isn't just a colorful mess.
Direction to go with is up for you to choose.