"▲ Show 20 Lines" ambiguous

When viewing a review, unchanged lines are elided. There’s a separator that says:

▲Show 20 Lines • Show All 91 Lines • ▼ Show 20 Line(s)

I have a hard time remembering whether ▲ means “show more lines from the block above the separator”, or “make the block below the separator expand up to show 20 more lines” - whether the triangle is pointing at the block to expand, or pointing in the direction that the expansion will happen.

I don’t have a really good answer. Stacking the three items

▲ Show 20 Lines
Show All 91 Lines
▼ Show 20 Line(s)

would make it less ambiguous, at the cost of vertical space. A stairstep presentation would be slightly less space, e.g. (but with half-steps so the total is two lines):

▲ Show 20 Lines
                                Show All 91 Lines
                                                               ▼ Show 20 Line(s)

Reproduction Instructions

View a difference with elided no-change lines.

Phabricator/Arcanist Version

I don’t seem to have access to a Config page, perhaps because I am a user and not an administrator. “arc version” wouldn’t run until I installed git, and then wouldn’t run unless I was in a git repository, and then claimed that I wasn’t in a git repository even though I was.

$ git status
On branch master
nothing to commit, working tree clean

$ arc version
The current working directory is not part of a working copy for a supported version control system (Git, Subversion or Mercurial).
(Run with --trace for a full exception trace.)

No other user has ever reported that this is confusing and users routinely complain when UIs are made less concise (or changed at all – see https://secure.phabricator.com/T3772 for a historical example), so I don’t plan to change this.

The arrow points at the lines it will reveal.