This aesthetic glass option would be used in place of standard clear glass. Low iron glass is ultra-clear, aside from the bluish-tinted edges it is almost barely noticeable when looking through it.
Tile viewed through low iron glass will be true to color without the obstruction of a greenish hue that naturally occurs in standard glass. It is also the best option for white bathroom décor and white tile because the glass is neutral in color providing the clearest option available.