Yep, a PR stunt.
What is the envoy to Lower/Upper Transesstan got to do with anything?
More importantly, the ambassadors to cushy countries where the most they have to worry about is wine selections. The main reason to get everyone in the room (besides the PR aspect) is to force everyone else down to her level of misery (and stupidity).
Maybe.... the 3 am phone calls are just too much for her and she's announcing that she's going to retire.
Funny she didn't say anything of note on any of the Sunday morning talk shows where she made a large circuit last weekend.