This is normally found on mirrors hanging on the walls with or without frames and glass tops. Normally on a glass top, there is not full support underneath the glass, so the bevel can be seen.
The glass is then processed through a bevelling machine. This is where a number of wheels focus on getting the grit finer towards the end. Then last of all the glass comes across felt wheels along with cerium oxide in order to polish the bevel back to clear. This creates a beautiful traditional look.