Cinnamon icons don't appear
Solution 1:
Try:
sudo apt-get install gnome-icon-theme-full
Solution 2:
That screenshot looks to me as if you're missing some icons- all the application icons appear to be there, but the icons representing categories of applications, as well as the actions to log out/shut down/etc, are not present. Perhaps Cinnamon by default selects an icon set that isn't present on Ubuntu? Try changing the icon theme in System Tools > System Settings > Themes to something like Ubuntu-Mono-Dark.