How can I change a display page to a photo?

Please read the following user tip and restate your question/problem in detail: 

     Writing an Effective Apple Support Communities Question - Apple Community

What do you mean by "display page"?

What system and Photos versions are you running?

As Old Toad implies, it's hard to know what you want. If you are talking about the screen that has thumbnail images, you could just do a screen shot of that. It might have menus and stuff you don't want, but you can crop that in Preview or in Photos.

Take a screenshot - Apple Support

Let us know some details if you'd like help...