How does the Finder determine the model of the remote host? This is metadata in the _device-info._tcp Bonjour service record that is the server advertises. My Synology helpfully shows up as an Xserve, in fact:
$ dns-sd -L "synology" _device-info._tcp local
Lookup synology._device-info._tcp.local
DATE: ---Thu 07 Aug 2025---
0:24:28.117 ...STARTING...
0:24:28.378 synology._device-info._tcp.local. can be reached at synology.local.:0 (interface 14)
model=Xserve
I encountered this when setting up a Time Machine volume for my wife. In samba shares you can set that value in smb.conf by adding
fruit:model=ModelX,Y
MacOS will accept plenty of device names that perhaps don't make sense for file servers (I have mine set to Watch6,18), but it makes sense realizing that Bonjour is used for a lot more than just network volumes.
The Finder shows these icons for network volumes.
How does the Finder determine the model of the remote host? This is metadata in the _device-info._tcp Bonjour service record that is the server advertises. My Synology helpfully shows up as an Xserve, in fact: