Produce the art for one card. The subject of the card will be John Von Neumann. He was one of the prominent mathematicians of the 20th century and among other things, invented game theory, oversaw the design and construction of the first programmable computer, and did the math behind early weather prediction. More information is at http://en.wikipedia.org/wiki/John_von_Neumann and all over the web.
The art should be representative of his accomplishments and abilities, not just a picture of what he looked like. Bring the magnitude of his accomplishments, intelligence, and creativity into the picture without just being a slideshow of his life. I haven't settled on a style (cartoony, comic book, painting-like, etc); this contest is a way to see the range of designs available, so don't feel constricted.
Format will be similar to popular trading card games, roughly half of of a 2.5"x3.5" trading card. I haven't worked how the printing size translates to pixels, but ithe picture should be at least 1024x1024 px. It may be cropped to fit the shape and size of the box when the card layout is finalized, but the whole art may be used on the website, marketing materials, etc.
For examples of cards from other games, see