You notice how her swimsuit matches the water? I've noticed this in a lot of good pics of fine-assed hos.
The color in the picture makes them appear more attractive, especially the coordination of the color of what they're wearing with the background. Bright, vivid colors makes a girl appear sexier and higher energy, like she's a fuck freak...
Meaning...
When guys jack to pictures, they're partially masterbating with the color but don't realize it.