Yes it's cheap and lazy but I find it vaguely amusing... (5 years and 1132 days ago)
I found the picture of a microwave, cropped it to get a closer focus on the microwave itself, selected it using the pen tool.
Selected window, copied it separately and deleted the center. Added the fish tank environment, resized it to match the size of the window, softened edges, added fish, added the window on top, changed blending mode to linear light and lowered opacity under 50% to get a better transparent look.
Colored the microwave using color balance and hue/saturation, added bubbles, fish and sea horse on the exterior. Added bubbles inside as well.
Added shadows and lights using adjustment layers and gradient tool. (5 years and 1809 days ago)