Yes, you can overlay pictures on your Iphone. To do this, simply open the two images you want to overlay in your photo editor of choice. Select the first image and then select the second image. With the second image selected, click on the “Layers” icon at the bottom of the workspace. A new window will pop up. Under “Layer Mode” select “Normal” and then click “OK”. Now you can move the second image around until it is positioned how you want it. When you are happy with the results, click on the “Merge Layers” icon at the bottom of the workspace and then save your images.