https://www.macrumors.com/how-to/use-visual-lookup-photos-ios/

iOS 15: How to Use Visual Lookup in Photos to Identify Landmarks, Plants, and Pets

Thursday July 8, 2021 10:55 AM PDT by Tim Hardwick

In iOS 15, Apple made further advancements in on-device machine learning and integrated them into the Photos app to make your iPhone more intelligent at recognizing the contents of pictures.

In other words, the ‌Photos‌ app can now identify various objects, landmarks, animals, books, plants, works of art, and more in your image library, and then offer information about them that it draws from the web.

This new intelligent feature is called Visual Lookup, and the following steps show you how you can use it to get more clued up on the things you’ve taken pictures of with your ‌iPhone‌ through the years.

1. Open the Photos app on your ‌iPhone‌ and select a picture with a clearly defined subject, such as a flower or animal.
2. Check the info (“i“) icon at the bottom of the screen. If it has a little star over it, tap it – this indicates there’s a Visual Lookup you can examine. 
3. Tap the little icon in the center of the photo to bring up the Lookup search results.

In Visual Lookup, search results consist of Siri Knowledge, similar images found on the web, and other online sources of information. For all the details on the other new ‌Photos‌ features in ‌iOS 15‌, be sure to check our dedicated roundup.