It seems that Safari 7.0 (for Mac) doesn't refresh the previews (anymore). Is there a way to turn this (back) on?
You can hit cmd+R while viewing Top Sites to manually refresh.
((I'm still trying to figure out how to restore automatic refresh.))
It is now no longer possible to refresh the Top Sites with Cmd-R (certainly it doesn't work in Safari 10.)
The only way I've found to do it is:
- Enable the Develop menu (Preferences->Advanced->Show Develop menu in menu bar)
- Choose Develop->Empty Caches
This will clear all Safari caches including Top Sites. The Top Sites thumbnails will gradually fill back in with newly-refreshed versions. (Very gradually—I assume Safari does it quietly and in the background, while it's idle. It took about five minutes for a new Top Sites tab I opened to gradually fill its thumbnails in as I was doing other things.)
This doesn't re-enable the "auto refresh" there used to be, but hopefully it might help someone like me who had a temporary network issue that seemed to corrupt all the Top Site thumbnails and just wants to force a refresh from scratch.