All the images except the footer background in the main & mini sections are required.
Keep this in mind before submitting any skin » don't use copyrighted images « hi5 just won't approve it :)
One last note:
"(How to) share a private skin
1. Go to your profile page, and make sure your skin is on your profile. From your browser's menu select View Source to bring up the code. (In Firefox, go to View--Page Source. In IE, go to View--Source.)
2. Search for or scroll down until you find this line:
3. Right underneath, there is a
4. Send this to your friends, and have them paste it in the Style box on the Customize Profile page. Make sure your friends remove any skin they might have on their profile, and any code they might have in the Style box before they paste in your skin's code."
Take care,
Fábio