You sure the ATV is connected to the network? I was under the impression it's supposed to show up automatically. Also, make sure in the Display Preferences the Mirroring Menu Bar option is checked.
yeah it's checked, but still nothing shows up, this screen shot was taken with a projector connected to my mbp. it used to be when I hook up a projector, a little mirroring icon will show up.
You sure the ATV is connected to the network? I was under the impression it's supposed to show up automatically. Also, make sure in the Display Preferences the Mirroring Menu Bar option is checked.
Apparently, when I upgraded from 10.7-10.8 it's still there. When I did a clean install on a another Mac the mirroring icon is gone from the menu bar. Seems like a bug to me.