Log/History select multiple line, how show?

[yang qibiao]

 t1.png

  t2.png

 t3.png

[minnsey]

Hi

If you select 1 line you see the diff for that commit.

If you select more than 1 line you see the difference between the oldest and the latest selected diffs.

So in your example in the first image you do not see the content of the 2018-5-25 commit, only the difference between it and the 14486 commit 

[yang qibiao]

thank.

but, why don't show all the selected?

[minnsey]

Sourcetree just reproduces the behaviour of Git