Mattis recently gave the commencement address at this school. Sounds like they enjoyed his visit.

The Hill reports:

Mattis receives honorary doctorate from international affairs school

Defense Secretary James Mattis donned his academic regalia on Saturday as he received an honorary doctorate from an international affairs school.

Mattis received the honorary law degree after his commencement address to a group of students at the Institute of World Politics, a graduate school in Washington, D.C., focused on national security and military strategy.

A Defense Department Twitter account posted photos of Mattis receiving a stole and posing for pictures with the graduates.