BRING IT TOGETHER

In Photoshop, open the Grid image. Open your first landscape. Press Ctrl/Cmd+A to select it, Ctrl/Cmd+C to copy and Ctrl/Cmd+W to close it; in the grid, press Ctrl/Cmd+V to paste it in. Set the Blending Mode to Screen so that it only appears in the black parts of the grid. Press Ctrl/Cmd+T for Free Transform Mode, then resize and reposition. Draw around the square you want it to appear in with the Rectangular Marquee Tool. Click the Add Layer Mask icon to mask it off. Repeat for the other three seasons.