Why are images from a logo from email signatures or disclaimers being autofiled as separate attachments in FYI?

Issue
We have email autofiling turned and sometimes the images from a logo in the email signatures, or from disclaimers, are being automatically saved as separate attachments in FYI.

Cause
Only genuine attachments are autofiled, and any attachments for images such as a .jpg, .png for a logo, signature or disclaimer are ignored.

However, when a reply is sent to an email, this may attach such images as full attachments.

Solution
These attached images should be deleted from the email chain to stop the autofiling.