Hi, I'm using
- SourceTree 2.1.2.5 on 64-bit Windows 10
- Git 2.13.2
- P4Merge
and I have configured P4Merge as the external diff/merge tool.

I have 2 branches.

testmerge - commit 5306ab6
This commit has pushed the following picture.

master - commit 09f5e69
This commit has pushed this picture.

Since P4Merge can diff pictures, I want to diff those 2 commits with P4Merge.

If I click that action, P4Merge returns an error.
I want to diff 2 commits to compare text codes or pictures.
Do I have to add "Diff commands" or parameters to diff those 2 commits?
Or is this feature impossible?
-Best Regards