R1:035067f83ce5

Show information about each image in the right-side gutter

Summary: Fixes T2646. Title and description are placeholders. Styles on this are a bit rough.

Test Plan: {F34623}

Reviewers: chad

Reviewed By: chad

CC: aran

Maniphest Tasks: T2646

Differential Revision: https://secure.phabricator.com/D5226