We didn't manage to get the icons for bug 425343 in time for the release, this is the tracking bug to add them. Andreas is working on them right now.
Created attachment 686183 [details] [diff] [review] Fix - v1
Pushed to comm-central changeset 52dee6ef1b23
Backported to releases/comm-aurora changeset e9df3c0baf0d
Backported to releases/comm-beta changeset a2deadc38a80
I will take care of 1.9.1 when I figure out where/how to best push.