A mull is a promontory. Mull can also mean to ponder or consider. Mulling wine, beer or cider is heating it with sugar and spices. Eg I went to the Mull of Kintyre and mulled over whether or not to have a glass of mulled wine.
Mull apparently can also be a form of non acidic compost or a particular type of muslim, so I suppose I could have sat on a pile of mull at a mull* in the company of a mull. We may have mulled things over together, but we'd not have drunk any mulled wine.
*Not Kintyre though as the soils is acidic there.
Now I could have mulled some wine and photographed that as I do like the stuff, but then I remembered how much you like my pictures of Scotland (or at least are too polite to beg me to stop, which is just as good) so here's one of the foghorn at the Mull of Galloway. (I don't actually know the man in the picture, but he stayed there so long I took the shot anyway, then walked down to see what he was looking at. It was a HUGE seal. He (the man, not the seal) then pointed out various different birds and explained about the tides and other interesting stuff.)