This simple trick is very easy to do, you only need the correct tools. It was my first time trying any such thing, and the results are pretty good, if I do say so myself. So here's a quick but extensive tutorial on how to make your own. You will need a camera, a tripod, a laptop, photoshop, and an imaginative idea. Simply seeing a wall with some plugs through your magical computer isn't exciting. To start off, place your laptop in its right background, and set up the tripod in front of it. Look through the camera viewer and re-position the laptop according to how you want it to look. Then take your first photo, with the screen open. Then, making sure to not move the laptop itself or the camera, close the screen and take the exact same picture. Check on your camera to make sure the pictures align perfectly, and that they aren't blurry or anything. If you don't like them, just repeat the whole process. I took about twenty different pairs of pictures before choosing the second ones I had taken.
The next step is the editing. BE CAREFUL! If you only have one computer, and you must do the editing on the same laptop, be extra careful no to move either the background decoration, the laptop and the camera. One centimeter could mean the ruin of the trick. The lid has been closed and when opened again, so angles won't be the same. However, look through your camera once finished with editing and re-align your desktop picture with the background. Open your pictures into photoshop. Copy one of them entirely and paste it into the other. When viewing your layers, you should have two One will be marked as 'Background', but simply double click on it and press save to make it into a layer. View the laptop open picture and with the Magnetic Lasso Tool, carefully go around the edges of the computer screen. Make sure you leave the actual borders of the computer out of the selection. Once the perimeter is selected, go back to your layers and select the one with the laptop closed. As you see it, you should also see the selection you just made on top of it. Right click on the selection and choose 'Layer via Copy'. Once done, un-view all other layers apart from the one just created, and you'll notice that it is twisted, and not at all rectangular. Go into the Edit menu, and in Transform, choose Distort. The image will have a sort of frame around it, drag each corner of the frame to align with the corners of the white rectangle around the actual image. Go up to file and choose 'Save As', and save the layer (make sure all other layers do not have the little eye symbol) as jpg, png, whatever your preference. Put the saved picture as your desktop background, and just double check to make sure it aligns in your camera viewer. All that's left is taking a final picture and showing off your cool transparent screen to the world! Alternatively, you could repeat the process enough times to make it look like an infinite number of transparent laptops. This takes a lot more time however, and even more care must be taken to not move the camera nor the laptop.