text message

A text message is text, or other data sent, or received through a smartphone, or instant messenger application.

Messages do not count as dialogue.
Text message containers should be tagged as message box instead of speech bubble.
Try not to confuse text messages with messages posted on social media (user message), or those posted in a streaming chat, or other public messenger (chat box, Discord).
Text messages may be associated with a profile icon. These may be tagged as user avatar.
Text messages may contain emoji, or emoticons.
Text messages may have a timestamp (number, time).