#VDG is finalizing a guideline for the use of emblems stating that they should only be used for non-default, uncommon, unusual, or unexpected statuses. This is described in D15897.
Accordingly, we should only show an emblem when a disk is unmounted, not when it's mounted. Being mounted is the expected status for a disk; being unmounted-but-visible-anyway is what's unusual and deserves an emblem.
As an added bonus, this hugely improves the look of the {nav Places} panel by default.
Closes T9740