In iOS 15 and iPadOS 15, you can enjoy multiple photos as a collection in your Messages conversation. Tap a collection to see it in a grid, tap a photo to see it full screen, and swipe to see the rest.
To learn more about this topic visit the following articles:
Send and receive photos, videos, and audio messages on iPhone: https://apple.co/3m3eikQ
Use Messages on your iPhone, iPad, or iPod touch: https://apple.co/3nkxoST
Use Shared with You on your iPhone, iPad, and iPod touch: https://apple.co/3m4lddo
Additional Resources:
Get Support for iPhone: http://apple.co/iPhone
To subscribe to this channel: https://www.youtube.com/c/AppleSupport
To download the Apple Support app: http://apple.co/2hFtzIv
Apple Support on Twitter: https://twitter.com/AppleSupport
For more videos, go to Youtube Apple Channel