Apple - Thumbnails for Image Files on Desktop won't load
Based on your log, I suggest trashing the Finder property list, then rebooting.
- Open Terminal
- Enter the following command
rm ~/Library/Preferences/com.apple.finder.plist
- Restart
- If the issue persists, I suggest following these instructions. to completely reset the service.
Further information: The X Lab's Maverick's Post Installation Issues