Circles and hearts.  The little hearts are those glass ready-made forms which one can purchase from a craft store.  The size they are in the final pattern of course is determined by the final size that you enlarge this pattern to.  If you make this pattern large, say 24 inches, you might want to just cut them out of glass.  Use a small hole grinding bit, or other small diameter bit do grind the center curve in these small hearts.  Check out a variation on this pattern at GospelGlass.