Are you referring to the Bing Wallpaper application for Windows 10? If so, please try the method below. Right-click on the Bing icon in the System Tray (Up arrow) on the taskbar You will see a short description or details of what the photo is. for example, it will tell you what type of animal it is or where a landscape was photographed. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.