Get computer name from IP-address
From the Terminal.app (or equivalent) you can use the host command to show the network name of the computer. This returns the name even if it has all sharing settings turned off and thus not showing via Finder.

For example, in my network I get the following (where I know the IP-address and the first part of the returned name is the computer's name)

➜ ~ host 192.168.2.135

135.2.168.192.in-addr.arpa domain name pointer raspberrypi.private.lan.


It depends on the actual name of the computer if the network name is exactly the same, as in your example, I guess it would become Jacobs-MacBook.