...
Cancelled, but thank a lot to everybody.

Thanks Microbius. I can't understand, 3 of these images are in the first page by popularity on SS and aren't enought good?  I have sold them a lot of times, so it's difficult believe that aren't enought good...but I accept that Istock isn't interesting in it and I close with this stock. But this time I want to tell that there isn't a so incredible quality standard on IS, it's simply different and subjective, like anywhere else. I have seen wonderful works and terrible works, like...anywhere else. 

Thank aeof, maybe they want only photographs...I'm quite exasperated. Really I'd like pass this examination only for personal pride.

Great depression 
When I made the christmas tree, actually, I have copied a christmas tree on Istock, I liked it, it was very colorful and nice...It was a very popular images, I think 3 or four years ago. 
Thanks a lot guys

Now I'm more confused than first (and a little bit scared  ) but thanks a lot for the encouragement Luiss. I don't try, I'm afraid

(sometimes I think that the only, real, important think is the lucky...if it's a good day for the examiner, he take everything but if it's a bad day there aren't possibilities...Like on Shutterstock, Fotolia and dreamstime, I think that, a lot of time there aren't tecnichal problems but only luck).

if I remember well you have photos and illust right? what application are you going to try?

I think that you should forget istock and concentrate more on other sites. You are going to beat your head against the wall trying to play their games and for the dwindling commissions they are offering, it just isn't worth it anymore. My opinion, of course. I hope you don't get discouraged, just keep trying at the other places and build your portfolio there.

You're very nice Clapper, I've your opinion too or, better, I think that your opinion is rational and intelligent but sometimes I' ve a masochistic instinct 

Just the type of contributor istock loves!