How did you start "Show log"? I get the same menu as you have if I start "Show log" from the Repository Browser. If I start "Show log" from within a working copy, I have the highlighted options. This sort of makes sense since the revert goes into a working copy where you have to review and commit it.
In the picture below I've started two different logs, the headline of the windows shows if I've started it from the Repository Browser (the headline is and URL) or if I've started it from a working copy (the headline is a drive/path).
Kind regards,
Daniel