The Shared section of Image Capture shows network devices that support scanning and the Bonjour protocol. So just by having a multifunction device on the same network that the Mac is on, and even when you don't have this device added to your Mac as a printer, it will still appear under the Shared section of Image Capture. The only way to remove it from the Shared section is to remove it from the Mac's network.
If you refer to the image below, I currently only have the MB5300 added to this particular Mac as a printer/scanner. Yet I can see all the devices on the local network that use Bonjour to advertise that they support scanning.
