You can make the application full-screen using the icon on the pop-up menu (bottom-right).
You can change the resolution of the virtual gallery using the pop-up menu. The speed of the application depends on your internet connection. If you have a slow connection, try using a lower resolution. If you have a fast connection then you will be able to experience the virtual gallery at full HD quality (1080p). If you experience any connection problems, you can refresh the page to restart.