Each year at Automattic, we take a full company photo at our Grand Meetup.
We receive a hard copy of the photo printed out and framed. While procrastinating and looking at these photos, I noticed several people stood in close to the same spot year-over-year. It became the topic for my flash talk.
I struggled a bit with a good conclusion and representing the data well. Chatting some with Kevin Conboy after, he threw out the idea to show people moving. I already had all the data, so built this bonus visualization.