A lot of times, less is more. It doesn't take but a few lines to determine a surface (e.g. her scales, the water) to get the idea across to the viewer. If I'd taken the time to do all the scales, the picture would have looked "busy" and lost any appeal it may have had.
Plus, I didn't feel like drawing out all the scales either. That would have been boring.
Don't get me wrong. Details are great to look at and I love looking at them. I just try not to do as much during the initial drawing. Coloring however...I can pretty much go wild if I don't go overboard.