Photo search, identification does not work. Configuration for enabling is not available or limited.

Are you trying to search for photos from outside the library like with Spotlight?

The library is build on a database, the phoitos are renamed when they are imported for easier merging with an iCloud library. The original file names are stored in a database and are linked to the photo it came from. You must be inside the library to search for file names of photos. Or for Titles you've add4d to a Photo.

The best way to search in a Photos library is with Smart Albums. There you can narrow down the search criteria with multiple features. My libraries have many smart albums, particularly the one I use for addressing user's concern about a photo library. I use a lot of screenshots and name them before I import, add the file name to the Title and, with keywords, sort them into groups.

These are all smart albums:

It's a necessity that one do the searching from within the library with the search tools provided.

Go to settings > search > show related content. If not on toggle it on. If. on, toggle it off/on

What exactly happens when you search in photos?

See visual lookup

What items within a photo are you trying to search for?

Photos spends a lot of time identifying and categorizing items in a photo and you can search for it with the search field at the upper right hand corner of the library's window. It cauterizes people, pets, plants, cars, tables, lams, beds, etc.

OT 

After reviewing a number of the recent photos on my own iPhone 17 Pro Max running iOS 26.6.1, I have to say that there are a lot more photos without meaningful Visual Lookup information than with it, but it does pick up some pet species and plant types (not always accurately).

You say you get no photos at all with extra Visual Lookup information (flagged with the "sparkle" on the circled-i "info" icon? No plants, no domestic animals?

On my iPhone and on my Mac the visual lookup is showing no useful results, most of the time.

Frequently the information button is marked with an asterisk, but when I try to view the look-up information it is empty.

For example, for this photo the visual lookup is stating "Nachschlagen: Denkmal" (Look-up: Monument). But the result is completely empty. The same happens for location information, when there is a badge with a location pin, an empty look-up result.

On my phone, landmarks sometimes are empty. Bugs, flowers, and birds do pretty well, but mammals are hit or miss. I have this picture of a lemur that, just playing around, I duplicated and removed color in the Mac's Edit mode.

The black and white lemur gets identified, by not the color one. Neither is identified on the phone.

That's weird, Richard. Perhaps it is working on the black-and.white version because you forced a new scan of the image by editing. I noticed that Photos will do a new scan for faces, when I retouch a photo a bit or crop it.

I can't get Photos to recognize my pictures of lemurs at all. Perhaps because they are nearly extinct.

The photos of lemurs have been imported in 2017, long before Apple introduced visual lookup. But reimporting does not help either.

On the other hand, Photos is recognizing dinosaurs as pets. There is a name tag below the face of a T-Rex:

I created a few video clips with Monster Park to test it. The face detection is tagging quite a few faces of the Dinos:

The T-Rex above is recognized as a Korea Jindo Dog by the visual look-up:

I can't believe you haven't named your pet T. Rex!