One of the small mysteries of the Eastern rite liturgy is why the priest obscures the view of the altar during the words of Institution. Well, now the truth can be told: because the Eucharist is the Resurrection, and who witnessesd the moment of Resurrection? That's right, no one.
Michael Dubruiel talks about the Eucharist and the Resurrection in his book "The How-To Book of the Mass":
The priest will break off a small piece of the Eucharistic bread and drop it into the chalice that contains the Precious Blood of Jesus while he says a prayer silently. This is called the co-mingling of the bread and wine. It is a small act, but rich in symbolism. First, it symbolizes the Resurrection of our Lord. At the consecration our Lord came to the bread and wine separately - this is my Body, this is my Blood; symbolic of His death on the cross. Now the two are joined.