Standard and clean themes:

• the picker content goes over the dialogue height. It's very subtle, look at the bottom of the dialog when changing repository. It's more obvious on clean. You can look on 2.4/2.5 for the good behavior, the full dialogue height is resized following the file picker content.

Clean theme:

• the header is blue
• "Upload a file" and "URL downloader" icons are too big

I also attached a screenshot of a css glitch on 2.4/2.5 about the top rounded corners. I initially took this screenshot to show how the file picker on 2.6 should look on IE9. It's not the object of this issue, so if it's not easily fixable on the go, you can write a different issue.