I, among many it seems, became quite frustrated when I discovered the MAC address on my Lenovo Smart Display wasn’t listed anywhere. It isn’t on the unit anywhere, it isn’t found in the Google Home App (now Google Nest app) and according to Lenovo support, it isn’t listed anywhere!
Well, I have a workaround that is going to seem obvious to many, but just the same, it works and I figured it was worth sharing. It is also a mobile-based alternative to a similar solution found here.
Step 1) Connect your Lenovo Smart Display to a WiFi service that doesn’t require MAC address verification. You do this following the normal device addition process within the Google Nest App on your phone.
Step 2) Once the Smart Display is activated and functional, use your phone to download an app that can identify all devices on your network. I am an Android user, so I chose my favourite of such apps, Fing.
Step 3) Make sure your phone is on the same WiFi network you set your Lenovo Smart Display to use. Using Fing, run an analysis of the network and in short order, you will see the smart display listed.
Step 4) Click on the Smart Display in the app and (if you are using Fing) you will see the image shown below, or a similar listing of network details including… the MAC address! Easy peasy.

Step 5) Record the MAC address, add it to the router (or another such security device) on the network that requires MAC address verification and then change the wireless account on your Lenovo Smart Display to match the one you want it to be on. With the MAC address matching the address in the new network, you should have no problem connecting.
TIP: I suggest writing the MAC address in permanent ink on the bottom of your Smart Display so you don’t have to go through all of this again in the future.