You can decide whether you want to include media files in internal chat transcripts, or choose not to do so to save on data volume.
The Account Owner can configure this in the organization settings.
Disabled: No media files will be attached to the transcript
Manually: The operator can decide which media files to attach
Automatically: All media files will be attached
Account > Organizations > click on the name of the organization to be edited
Screenshot of the "Manually" option in Message Center