I don’t know off the top of my head but I’d be surprised if macOS runs a DCHP server unless it is setup to “share its internet connection”. If you can’t get it to work I can do some experimentation later today.
UPDATE:
@fac_6 - I just tested out a direct ethernet connection with my MacBook Pro (a late 2016 touchbar model). If I open up System Preferences and select Sharing, Enable “Internet Sharing” (on the right) then select the network interface with norns attached on the left (which in my case is a USB-C gigabit ethernet adaptor) - then everything works.
…once sharing was turned on I could use norns.local in a browser to get to maiden and connect to it with ssh, sftp, etc. in a terminal. As a bonus if your laptop is connected via WiFi to another network with internet access norns will have access to the internet as well. In my case norns was given an IP address in the 192.168.2.* range once internet sharing was turned on.