No structure and no anthropomorphic figure
The truth is, abstract art is not “about nothing”. At its basis, it is about form, color, line, texture, pattern, composition, and process. These are the formal qualities of artwork because they describe what the art looks like and how it is created. Abstract art is an exploration of these formal qualities. Meaning is derived from how these formal qualities are used to create a visual (and/or visceral, cerebral, emotional, etc) experience.