Code review comment for lp://staging/~laney/ubuntu-system-settings/lp1631997

> Is XDG_CURRENT_DESKTOP set? It certainly worked for us in yakkety's unity 8
> desktop session where it is set to Unity:Unity8.
>
> NotShowIn=Unity isn't a great idea, for your reason, because
> XDG_CURRENT_DESKTOP contains "Unity" already in U8 on desktop (as I just said)
> and because the moment that U8 supports Only/NotShowIn properly then things
> will stop showing up if XDG_CURRENT_DESKTOP contains "Unity" elsewhere too -
> and it would be weird for it to be different depending on how you get into
> Unity8.
>
> I think that it's preferable for OnlyShowIn to be properly supported instead.

XDG_CURRENT_DESKTOP is not set on the device. Also dobey said the scope doesn't do anything to filter that out anyway, but I'm pretty sure the icon was showing before with this branch in the silo.