What does he mean by this?
What Adams implies in this statement is that the quality of a photograph depends heavily on the angle from which you take it. Therefore, he implies that the perspective of the photographer on a particular object is much more important for the quality of a picture than the object being photographed or even the skill of the photographer.
How does this apply to landscape photographs?
This is particularly important when photographing landscapes. When taking a picture of a landscape, it is impossible to change the object of the photograph itself. However, what we are able to do is move the angle from which we take the photograph.
Do you agree or disagree with him? Why?
I agree with him, because almost any object can be the subject of a good photograph. Sometimes, the best photographs are those that show mundane objects and landscapes but are taken from a perspective that is special or unusual.
