By definition, frames and mounts are enclosing devices, but in the world of Photoshop anything is possible. Here, subject and frame interact; 2D melds with 3D, complete with the interplay of shadows. The key to this project is the stacking order of multiple layers; the use of a Bevel and Emboss layer style completes the illusion. This is a great technique for adding an extra dimension to images.
1 Open the image of the swan. Use the Rectangular Marquee tool to make an off-center selection, ensuring that the swan's beak and part of its head project outside the selection itself. Go to Select > Inverse (Ctrl/Cmd+Shift+I) and right-click/Ctrl-click within the selection, choosing Layer Via Copy.
2 In the Layers palette, rename the new top layer "Swan's Head." Ctrl/Cmd-click this layer thumbnail to make a selection from its transparency. Then return to he background layer, add a new layer (Ctrl/Cmd+Shift+ N), and call it "Mount" Choose a light straw color for the foreground and click inside the selection with the Bucket Fill tool.
3 Hit Ctrl/Cmd+D to deselect and click on the Swan's Head layer. Add a layer mask, using Layer > Layer Mask > Reveal All