Replace 'Embed' hint on Pholio
Summary: Replaces Embed hint with where the heck you are hint.
Test Plan: Tested current and previous mock images.
Reviewers: epriestley
Reviewed By: epriestley
Subscribers: epriestley, Korvin
Maniphest Tasks: T5384
Differential Revision: https://secure.phabricator.com/D9658