Just to be clear, I’m talking about a local installation of Outlook – in my case, Outlook 2013 – and not the web interface of Outlook.com.
Because I use this email for my primary Facecebook address, all of my emails looked like this…
I had to do a lot of searching, and ran across a lot of people discussing the problem, on Facebook and at Microsoft and even over at Google, but it was this one page from Microsoft that gave me the clue…
All of the other solutions were pointing to a setting that I couldn’t find, that involved looking for a way to disable “Disable content from third party networks”, but that wasn’t it.
Outlook Social Connector Add-in
The culprit that was grabbing my photo was an Outlook Add-in called the “Outlook Social Connector” and all I had to do to disable it was disassociate my Facebook account from the “People Pane” under account settings.
Another method would have been to remove the Add-in entirely, and here’s a fast two minute video that will show you how to take care of it with either option.