Knowledge base
The ability to share photos with friends and relatives is a great feature of the Messages app and it is one of its primary uses. Showing off holiday snaps, weddings, birthdays and other events with your contacts is great fun. We used to have to do it one photo at a time, but now it is possible to share whole collections of photos in one go. All you need is iOS 15 on your phone (it works in Monterey too).
Messages on the Mac
A photo collection is like a stack of photos, so instead of a dozen images in a long vertical list in a Messages conversation, you see a stack of images instead. You can browse the images and save individual ones or the whole lot. It keeps the Messages conversation cleaner and simpler.
The Mac is not as restricted when it comes to sending photo collections. In addition to selecting images in the Photos app – it is possible to select photos in a Finder window and then drag and drop them to the Messages app. All the photos are added as a collection. This is a really useful way to create collections.