I try to make Choices slideshow usable for high res displays. For that I use WP Retina 2x plugin.
The image first loads well (high res), than after a second (max) falls back to low res version. When I right click the image and open in new window, the right version of image (high res) appears. It is visible on the iPhone 4 as well, not just new MBP.
This issue is NOT present in Chrome Canary, so it is not related to plugin I use for serving high res versions of images or custom CSS (tried to remove all just to be sure). This should be some theme script problem involving Safari.
The web is: http://fotografie-realizaci.cz
However, this bug can be seen as well on the demo site of Choices (and when open the demo slide in new window the image is visibly sharper than in slideshow - although its not high res I assume).