Inconsistent cursor behavior during staging

[Perlence]

Hello! I've discovered that if I stage a file when the index is empty, the cursor goes down. For example, after staging status the cursor moves down to init.vim:

However, if I stage a file when the index is not empty, the cursor goes up. For example, after staging init.vim the cursor moves up to tmux-sessionist:

It's a bit confusing, is this behavior intended? I think a more friendly way would be always moving the cursor down on staging unless it's the last entry in the group (staged or untracked files).

I see this behavior on tig v2.3.0 and on the master branch.