I download an iPhone mockup PSD and it looks like this:
As you can see, there is a placeholder layer at the top that says "YOUR ART HERE". I'm not sure what to do though. The mask works: I can only draw on that layer within the boundaries of the mask. But when I try to paste my app's screenshot into that layer, a new layer is created. How can I paste into this layer with the mask? I have tried merging the pasted layer down, but that destroys the mask or the layer.