Same picture several times in a project?

What kind of project?

if you are creating a book or calendar or card, you can switch the film strip with the photos to "Placed Photos" and then you can add the same photo to additional photo boxes, for example:

For a slideshow select the photo in the Moment, then use the key combination ⌘D or "Image > Duplicate" to to create more versions of the same photo and add the additional versions to the project. "Duplicate" will not actually duplicate the imported original file. All versions will share the same original.

For example - the same photo several times in a slideshow:

You're welcome 🙂 Glad to help!