Attaching photo in messages MacBook Pro

Hey Cid Gillispie,

Thanks for using Apple Support Communities. I see that you're wondering how you can attach a photo in the Messages app on your Mac and I'm here to provide you an answer to that.

You can attach a file or a photo by using the Finder app. Open the Finder app > right click on the file or photo you wish to send > select 'Share > Messages' from the menu to create a new message. This will open up a small dialog box directly over the Finder window that allows you to enter the recipient information and a text more before you send the image.

For more information, check out this resource:

Use Messages and Mail to share photos from Photos on Mac

Have a great day!