How to get my iCloud synced Photos library to show up on my old Mac after migration to my new Mac?

My old Mac: late 2013 MBP with 512 GB. The Photos library wouldn’t fit on the internal SSD, so it’s been on an external SSD.

My new Mac: Brand new 2021 MBP M1 Pro with 2 TB internal SSD. After migration I moved the external Photos library to my internal drive.

I have 2 TB of iCloud storage and have been syncing my Photos all along, so they are in iCloud.

On my old Mac I changed my iCloud settings to “optimize disk storage.” That’s the only change I made.

If I open Photos it says it cannot find the Photos library. I tried finding it in Pictures, the new location on my new MBP, but it doesn’t seem to be there.

Any suggestions?

Thanks.

I just had to click “create new library” and make sure the preferences were set right to use that library, and make sure disk optimization was turned on and it’s syncing very quickly now.

I’m curious how it all looks when done with disk optimization turned on.