I did this piece for a group called Grovemade as part of their Artist's Series. They make these amazing bamboo and leather cases for iPhones and iPads. Check them out here http://www.grovemade.com
There really were no parameters other than working in something that felt like my style. Be sure to check it out on there product page and pick one up if you think it looks cool. I will add a link to this page as soon as they are for sale.
The illustration of the vulture was done on the iPad with Adobe ideas and then the illustration was finished in Adobe Illustrator. Kinda felt cool illustrating a case design for the iPad, on the iPad.