Is your feature request related to a problem? Please describe.
When viewing the obslog I find it much easier to view the change the the previous commit as opposed to the previous change. Using jj directly you can do jj obslog -p.

Describe the solution you'd like
An option when viewing a obslog to switch to patch mode

Describe alternatives you've considered
I wrote a fzf script myself to do this before I realised vjj was a thing.

Additional context
It's actually pretty awkward to do as there isn't an easy way in the jj cli to get the previous commit id. In my quick script I had to get a hashmap of the commits and use the index to work out the immediate ancestor and then call interdiff.