Can't really see clearly. If it is one piece of glass then it is mirror with parts of the mirror removed and painted black. This is all done from the back. Then you will get a nice continuos glass. This should be the rite way to do it.

A cheaper alternative would be use mirror and black painted glass strips.

Both will need timber backing to mount. Cost of mirror about RM25/ft2 and timber backing about rm15/ft2. Ask around for better price. Note that if you use cheap mirror and back painted glass after a while the glue might actually peel off the mirror layer...