This issue is isolated to Internet Explorer 11. In order to be able to upload a photo to the PrintAd step via the Features tab (Photo in Print upsell) the user needs to add the domain "adperfect.com" to their list of Compatibility View sites by following the steps below:
1. Click the Tools gear in the top right corner
2. Click "Compatibility View settings"
3. Click the "Add" button in the box that pops up
4. Click Close when "adperfect.com" is under "Websites you’ve added to Compatibility View"