Desktop Image Viewer
From Xojo Documentation
The Image Viewer control provides an area in which you can display a BMP or PNG image on Windows and Linux or a JPG or PNG image on macOS. You can easily program the Image Viewer control to accept a dragged picture.
Image - The image to display.
Do display a picture in the Image Viewer, set its Image property. This code in a Button's Action event assigns a Picture that is included in the project: