That's interesting, since there is other threads that discuss Home sharing not working.
I started one of these threads. My Home Sharing option is available, but it does not list a photos option.
Even though I have Turn on Home Sharing and specified the folder for the photos to be shared, the Apple TV does not display this folder. IT does not even have the listing for Photos.
I even tried this on a fresh Mac Mini. Wiped it clean, installed Catalina, Logged in with My Apple ID for iCloud, etc, Connected it to the same Wi-Fi network as the apple TV, Turned on Home Sharing, specified the folder of Photos to be shared.
Still nothing on the Apple TV.