You can go into Seller Admin > Edit Profile > Upload Your Logo to provide a custom logo/header that will appear on your checkout pages (for payment processors which support it), E-junkie thank-you pages, E-junkie Marketplace Shop pages, and the "fallback" version of our cart that appears in a new window/tab if JavaScript is disabled.
To unlock that feature, you must join our Reseller program by posting your E-junkie Reseller link code to any live Web page. You will earn 20% of the monthly subscription fees paid to us by anyone who clicks your Reseller link before registering for their own E-junkie account. See more details here:
http://www.e-junkie.com/ej/reseller.htm
Once you have done that, this page explains how to add a logo into our standard overlay-style shopping cart:
http://www.e-junkie.com/ej/trouble.reseller.custom-logo.htm