There are a few steps you can take to create a mirror image in Photoshop. The first step is to select the object you want to mirror. Next, click on the Mirror button in the bottom left corner of the Photoshop window. This will open a dialog box that allows you to choose how much space your image will take up on the canvas. You can also choose whether or not to have a mirrored background. Once you have chosen your options, click on OK to close the dialog box. Now that your object has been selected, it is time to create the mirror image by clicking on the Mirror button again in the bottom left corner of the Photoshop window and then selecting an image from your photo library. Once again, be sure to choose how much space your image will take up on the canvas and click on OK to close the dialog box.