ok, this picture is full of little details. It´s very symbolic, too.
It comes from the the bible where it compares the church to Jesus´s bride. the fire is God´s presence... it´s related to passion and purification. Metals are cleaned up of their impurities by fire.
there´re 3 eyes on the back, Father, Son and Holy Ghost. notice that the shine in the first eye has the bride´s shape.
the reason they seem kinda sad is because they love each other so much... and they´re willing to be together forever! but they can only be face-to-face in the end of times. They´re not really sad, but filled with passion, waiting for each other.
'The Spirit and the bride say: ´Come!´. And let him that heareth say: ´Come!´. And let him that is athirst come. And whosoever will, let him take the water of life freely.' Revelations 22.17
Come Jesus, and take us with you!
got the background picture at getty images: http://creative.gettyimages.com/