Not yet, but in the future this kind of use case may be supported by an XMTP message format that includes rich media as hyperlinks. Clients may provide a UI that would allow for seamless uploading, retrieval, and display of files hosted outside of the XMTP network.
The contents of a message within XMTP is represented by a string, which is typically encrypted. The string may contain references to media that is stored elsewhere, which could be interpreted by clients to resemble an attachment.
Sending rich media as a part of the message itself will be discouraged as there will be a size limit placed on messages.