Click on the visualizations to see it in action. The purple areas are areas a user highlighted to tell the system to inpaint, and when you click on the image you see the results of the inpainting. Basically the model redraws sections of an image (the purple areas) using the context of what's in the non-purple areas to decide what might look best in the purple areas. Often used for removing objects but as you can see in the examples it can do other things too.