You’ll know when the change has hit your phone because the first time you open the app after the update, you’ll be prompted to enable Google Photos integration for the Messages app. “Share videos as they’re meant to be seen” reads the prompt followed up with “Preserve sharp video clarity when you sign in and send Google Photos links.” A link at the bottom of the page allows for the use of the Messages app without a Google account.
You will have a couple of choices that you can toggle on including one that will always send a link to Google Photos when you use Messages to share a video by text (SMS/MMS), and another option that will always send a Google Photos link when you text images via SMS/MMS. By allowing the Google Photos link to be sent with videos and images, you are giving the recipients of such content via Google Messages the ability to view them in a higher quality than if you sent them via MMS.
If you’ve received complaints about the quality of the videos and pictures that you’ve shared via Google Messages, this is a clever way to send higher quality content using that app with an assist from Google Photos.