First of all, regarding the picture issue you can see the answer I gave Sporadic. I understand your request and a blurred picture would be fine.
As for the winner, it is clearly stated that the best review will win. Meaning, reviews will be graded by creativity, effort and how useful they are.
Note that there is also an option to submit a video of a review of anything else related to eBook readers for that matter - that kind of format can substantially increase chances of winning since it is consideref "more effort" than just writing a review.
Hope this clears things up.