......but here is a video .....that google made? .....WTF? https://get.google.com/albumarchive...V36ii3rQHUuJ1CpHSOPJtA?authKey=CPmi-fjVpYmdRA
You watch that without some of the back story we have here it, at time, looks like you may have murdered and eaten some hippies in the backwoods...
Yah.. didn't know it had music... watched the video without sound.. BUT the most likely answer to your question is they use the same type software as FB does to do their year in review videos. It snatches photos you might have shared or posted or sent and puts them in calendar order. Then its super simple for them to lay music over it and bammmm hey have a video for you. if you have a google circles or plus what ever they call it then that is likely the culprit......
Right if they're gonna invade your privacy they should at least look into your musical preferences too...or did they?
Welcome to the world I ave been warning people about for over a decade. Seems like I recall something being reported that when you post pictures to those sites they have an interest in them. FB tried altering their terms of service a while back to allow them to use your photos. You didn't really think that these people give stuff away with no payment whatsoever, did you? They just don't always ask for money, sometimes they just require you give up some privacy or even your soul.
Not sure how they do it either but I get a few of these a year from them. Always turn out to be pretty good vids.
Dramabook does the same thing. It's a "feature" that's built into google photos that takes random photos from your google drive/google photos storage and makes a memory collage. You can choose to post it or keep it away from prying eyes, psychotic exes, clowns and general weirdos.
I would hate for them to put some of my albums (I only use a paid Photobucket account) to music... they would need the score from Lord of the Flies, Out of Africa, Studio54, Miami Vice and whoever it was that wrote all the background tracks for the 70s porn to do it justice...