Yup, some themers have a bit of extra time to composite a "screen grab" I'm photoshop or paint.net. I haven't done that with mine, nor do I worry about with others. It's so easy to download a new fw, flash it, and see if I like it. There's a lot more than just a nice looking "screen grab". The fw needs well thought out navigation. I've really enjoyed @AsianInvasion's and have used them as a base for further modding. If you're interested try out the dark FW2.4 version of Fragments Blue I threw together. I posted a link recently.
This took a minute
In your way someone might take 15 minutes downloading... not liking.... then going back to the previous one because they didn't like the G.U.I. which is what the average person maybe cares more about than a themers pride or whatever prevents them from introducing their creation in a manner that took me less time than typing this.