The 570 has a replaceable window to allow you to tweak the look of the side of the case to your own taste. The aluminium mesh is held in place with a series of screws and clips. The mesh is fairly easy to remove by unscrewing the screws and, err, unclipping the clips.
Gigabyte includes an acrylic replacement if you want something a little more see-through. This can be clipped in place and screwed back down in just a couple of minutes. The fact that the company includes the spare panel, rather than charging extra for it, is definitely a good thing - we look back on the days of extortionately priced window-panels for aluminium cases with some disgust.
Job done. Fairly simple, huh? Obviously, you can do something cool with the acrylic if you're in that kind of mood - maybe bust out the Dremel and get etching?