How to edit a Smart Object in Photoshop: If you want to edit the contents of a Smart Object, you can do this manually, one at a time, or you can automate this process. To do this manually, double-click the Smart Object layer, which will open it up in a new tab. You can then place your desired image at the top of the layer stack, size and position it to your liking, then save this tab to update the Smart Object in the main document. Another technique is to simply right-click the Smart Object, click Replace Contents, then select your desired image.
If you’re performing a large number of Smart Object replacements—for example, when creating mockup images—you can save tons of time by automating this process using the Batch-Replace Smart Objects plugin. Simply specify the Photoshop Document To Use, the input folder (which contains your images), and the output folder to save to. Then, just click ‘Run’ and it will automate the creation of all your required mockups. If needed, you can save operations to run later, and you can also chain together as many operations as you need to automate your entire workflow with one single button click.
If your goal is to edit the Smart Object itself, certain transformations will be allowed while this layer is selected, but other changes require that you rasterize the layer first. However by rasterizing the layer, you will no longer be able to replace its contents to create mockups. If your ultimate goal here is to change the appearance of the mockup scene while still being able to use the Smart Object to make mockups, one solution is to add a layer on top of the Smart Object, and apply your desired changes to that new layer. Also note that you can apply Effects to Smart Object layers without rasterizing them, and you can also create Adjustment Layers whose changes will only apply to the Smart Object layer if you link them via a Clipping Mask.
