I think it’s pretty darn clever on their part.
By now you’ve probably all done this. Dug up your first profile pic to compare how you’ve changed (or not) in the last 10 years. Whether you posted it or not, I bet you looked 😉
Anyhoo, there were rumours that it was to help the FB machine learning algo with its facial recognition learning classifications. And I think it’s a very good idea on their part.
With all their users and such a huge database, they got everyone that participated in this to willingly give them information to help them train their bot. At the end of the day, it just helps with its training so they can become better and better at facial recognition & changes over time. Think of all the good some of that training might do one day? If a kid or young adult is lost/kidnapped/runs away whatever, and years later the software is run through some country’s camera network or whatever, it could pick them up and alert authorities. Or used on criminals on the run.