You see on the bottom those “Folders” or whatever? That’s gone. No swiping to access the most recent pictures.
It’s a completely new app. Looks different, it acts different, the gestures are different, some icons (like editing) look different.
There’s customization options, this requires work, and no, you can not customize it the way it was.
Isn’t it at settings - apps - safari - then somewhere in the middle?