Hi there Al_H,
We understand you have a question about using the Photos watch face, and we'd like to see if we can assist.
Get started here: Apple Watch faces and their features
Specifically, this information under the "Photos" section may help:
"A new photo appears every time you raise your wrist or tap the display. Choose an album, Memory, or up to 24 custom photos.
Create a Photos face on your Apple Watch: With the current watch face showing, touch and hold the display, swipe all the way to the right, tap the New button (+), then tap Photos. Or, while browsing in the Photos app on your Apple Watch, tap the Watch Face button, then tap Photos."
Keep in mind, you'll need to have the storage space available on your Apple Watch to sync the album over to see them on the watch face. This page may help: Choose a photo album and manage storage on Apple Watch
Cheers!