Google Photos is returning with an interface which was thought it outgrew
Google always likes to switch up its style and this is why Android 12 had a shift in appearance with Material You. With an all new design philosophy all of its apps will follow the suit whether with the dynamic themes or the bottom navigation bars. We often not see Google switch back to an older design but with a surprising change in Google Photos, the company seems to be setting a pattern with its current trends.
Google Photos has briefly flashed a three-line hamburger menu in the app before it disappeared after the restart. When tapped, the icon dies not do anything. It just lights up without opening a specific menu or performing any other action. So it is still not clear that it is a bug or Google is testing to roll out to users eventually. It is also very interesting that Google Messages app was recently updated to feature a new three-line icon which was not featured previously. There menus have been removed from Android apps over last few years