If filename is not set or the value of both properties are identical, this is the filename of the original upload. Otherwise, this is a caption for the file.
OptionalfileRequired if the file is encrypted. Information on the encrypted file, as specified in End-to-end encryption.
OptionalfilenameThe original filename of the uploaded file.
OptionalformatThe format used in the formatted_body.
Optionalformatted_The formatted version of the body, when it acts as a caption. This is required if format is specified.
OptionalinfoMetadata about the image referred to in url.
One of: [m.image].
OptionalurlRequired if the file is unencrypted. The URL (typically mxc:// URI) to the file.
Content format of media events with msgtype
m.imageSee
https://spec.matrix.org/v1.11/client-server-api/#mimage