You can easily change the look of the Minecraft PE world with textures and shaders. Textures only slightly change the appearance of the content, and shaders make it as realistic as possible. Your world gets new shades, animation and lighting. Shaders will make realistic water, a real shadow from the sun and the correct animation of the waving leaves. Not all devices will be able to work with large shaders, but even for weak devices, you can find your own improvement of the world in MCPE.