daveinsouthcentral
Member
If you created a .nomedia file, try deleting it. (you can move it to a PC temporarily to see if this works)
Gallery looks in Media Scanner's database to see what files to display. (Otherwise every time you ran Gallery it would have to stop everything to scan the entire phone for files.)
Taking a picture triggers Media Scanner to add the picture to the database. Recording a video or sound file triggers it. Downloading or copying a file doesn't trigger it. So Gallery isn't aware that you downloaded or copied that file. You can restart the phone to rerun Media Scanner, or you can install media.Re.Scan and make it rescan any time you change things (like downloading a media file). It's free, it does the job nicely and it works with KitKat, Lollipop and Marshmallow. (And it doesn't use any resources except for 8MB of storage unless you're running it.)
You'd have to access those files from within the Google app itself. Open the Google app, tap More>Collections>Favorite Images, and I think you'll find them there. I don't think you can download them from there, though -- you'd have to go back to the website where you got those photos (or repeat the Google Image Search for them) and re-download them.