Yeah...couldn't really explain it though. Is that right, or am I an idiot? Although you can of course move the 100% view window.
Well, thats kind of sort of it. The one thing that I need to point out is that you are not restricted by the size and shape of the 100% view window. The size and shape of the area cropped can be any size and shape, so long as it is presented at 100% when done.
So for EXAMPLE, if I took a picture of this post, and I wanted to crop to word, "example" that is in red. You can see that that would be much smaller that the 100% view window, yet is it still a 100% crop if viewed at 100%.
Again, now for the purposes of posting here on POTN, we have a size limit of 1200 pixels across, and therefor, you would want the final result crop to be no bigger than 1200 pixels in the longest dimension. But that is a POTN limit and has nothing to do with the definition of a 100% crop.
Rad

