Sony Xperia XZ3
Writing and sending picture messages
A picture message is a message which can contain pictures and other media files and can be sent to other mobile phones. If you can't send and receive picture messages as soon as you've inserted your SIM, you need to set up your phone for picture messaging.
Press Messages.
Press Start chat.
Press the field next to "To" and key in the first letters of the recipient's name.
Press the required contact.
Press the text input field and write the text for your picture message.
Press the attachment icon.
Press the picture icon and go to the required folder.
Press the required picture.
Press arrow left.
Press the send icon when you've finished your picture message.
Press the Home key to return to the home screen.