Its definately not a vector. Looks more like a digital painting, in which case, you need to have more values. More darks and more lights. The shirt looks pretty good. Did you use the eminem photo as a reference or did you work over it?

A raster is the opposite of a vector. Photoshop for example is a raster based program. A raster image consists of colored pixels. Hence when it is enlarged, quality lessens because those pixels are being stretched.
A vector on the other hand is not made of colored pixels. Illustrator is an example of a vector based program. Vector shapes are defined by mathematical equations so you can enlarge all you want and the quality will never decrease. Because they are defined by mathematical equations, they are somewhat limited often causing the image to be simpler than a raster image is able to be.

Tell me how you did it and I'll let you know what it is.