The male (right) Mountain Bluebird was thinking that the female was going to give him the yummy grasshopper she had in her mouth. When she didn't, he looked surprised and disappointed, don't you think? LOL
I have used it a few times in the last couple of days and I am very impressed. As Nick said, if things look a little off, you can just make a second pass with the brush and it usually comes out great.
I have never found or heard of a third party battery that works as well in a Nikon as an actual Nikon battery. They are expensive, but they work and hold a charge.