Transfer and Edit Photos Albums from my Mac to a separate Mac Mini

Need advice about transferring and then editing my Photos library and albums (from my desktop Mac) to a separate Mac Mini device. The situation is, on my desktop Mac I have about 20,000 family photos in my Photos library - these photos are distributed into 50 albums - all photos in the albums are edited, sequenced and titled.

As a gift to my brother, a PC user, I want to give him a Mac Mini, loaded with an edited version of my Photos library. My brother's Photo library would then look something like 6,000 total photos in 15 albums. How do I best go about creating his edited library?

My thought is to make a copy of my library and then past it into the Mac Mini, Photos app. Then delete from the Mac Mini Photos library the 35 albums not for him. This should be fairly simple, however I suspect the 20,000 photos in the library will remain, right? Is there any way I can restrict the library on his Mac Mini to only the 6,000 photos that will be in the specific 15 albums I want to share with him? The alternative is I will need to spend hours deleting the 14,000 photos in his Mac Mini library that are not intended for him. Any thoughts on how to achieve creating this edited / reduced version of my library, in an efficient way, that keeps the quantity of library photos in the Mac Mini the same as in the 15 albums?

Thank you,

HDP