Unfortunately, I can’t give you access to the site as I am working offline. The best I can do is providing you with a screenshot : https://drive.google.com/file/d/0B1GYMkYwaFjnMTRQRUszX18xdE0/edit?usp=sharing
I experienced this “problem” with the preview but I thought this was due to the icons chosen. I couldn’t expect such variations between retina and non-retina rendering.
Thank for your help.