It doesn't look like anything and it's not supposed too. Not exactly what we think of when it comes to art. It's supposed to look like something isn't it? Fruit in a bowl, a landscape, or people doing something that is what art is supposed to depict or so many people believe. For many viewers of art, particularly painting, there is a subconscious idea of the picture plain as a window, a window into a scene. Abstract art disrupts that idea, so many have a hard time understanding it.
Abstract is the kind of art people look at and exclaim, "I can do that!" or "My kid could so that." Those people are certainly entitled to that opinion. As a viewer or art I have felt that way about many pieces. As an artist who works abstractly, however, I would ask, "Why didn't you?" As my favorite art teacher of all time used to say, "Anyone can draw and paint, but it takes an artist to be creative." The difference between you, your child and that artist is that he or she had the idea to make that work, where you have just exclaimed that you could after seeing it.
To understand abstract art, we must 1st explore abstraction. What makes a piece of art abstract? The best answer I can come up with is that abstract art is any piece of art in any media that is not representational of naturalistic scene, object of person(s). You may agree or disagree with this definition, but it is the one I am working with. This for art rose to prominence during the modern period. What art became about, for the most part, was itself. Now that doesn't mean every piece of abstract art is completely about itself, but I would argue that a large bulk of it falls into that category.
So when viewing an abstract piece and keeping in mind that, unless directed differently, the piece you are viewing is about itself questions must be asked. The process of asking questions and making observations is important to all art viewing but particularly for abstract art. The observations will vary depending on the medium but here are some things to take note of:
For 2 dimensional work
Line work
Brush strokes
Size
Color choices
Choice of material (paint, pencil, charcoal etc)
Negative vs. positive space
For 3 dimensional work
Medium
Process
Color or lack there of
Size
Shape
Negative space
Observing these different criteria and asking the question of why will bring understanding. As you follow this viewing process, you relationship to the work will change. It will no long be something that you kid could do, but rather the valued art work that the people around you see.