Hello, thank you for reaching out to Microsoft Q&A.
Are you referring to the photos shown in the My Paintings section of the Fresh Paint app?
If so, you can delete a painting by right-clicking the one you want to remove. A delete (trash bin) icon should appear in the left pane - click that icon to delete the selected painting.
If this is not what you are trying to do, could you please provide more context about the issue or share a screenshot of the painting you are trying to delete?