Celebrants and adding "signatures" to Mass

Over the past couple years or so, I've noticed something some celebrants do at the preparation of the gifts. It didn't really bother me so much as puzzle me.

Generally, the priest first offers the bread. "Blessed are you, Lord, God of all creation; through your goodness we have this bread to offer..."

He then prepares the wine, praying inaudibly at first, and then: "Blessed are you, Lord, God of all creation; through your goodness we have this wine to offer..."

Then, after another inaudible prayer (which could be found in your missal), he washes his hands, praying (again, inaudibly) for his sins to be washed away.

I've noticed that some priests do it a bit differently.

The prayers are the same, but they prepare the wine first, placing the chalice on the altar, offer up the bread and the wine immediately afterward, and then perform the hand washing ritual.

No big deal, right?

Probably not, but as I said, it's puzzled me for some time and today I asked a priest about it. He didn't know the answer, never really came across it. But he added something I thought a tad odd:

"Some priests have their own `signature' when celebrating Mass."

Now this did intrigue me. In fact, it got me to mention other "different practices" I've seen. For example, the loud verbalizing of prayers to be said inaudibly. The neglecting of hand washing. The additions to the various Eucharistic prayers.

Again — and, to be fair, the priest was probably busy and not quite up for a liturgical discussion and anyway, I'm no liturgist — he repeated the odd comment about the "celebrant's signature." And assured me that so long as the celebrant didn't change the words of consecration, there wasn't really anything to worry about.

Actually, I wasn't worried...only on my way home I couldn't help wondering.

About why some priests don't reverence the altar. Nor kiss the altar upon entering the sanctuary. Nor kiss the Book of Gospels after proclaiming the Gospel. Or, why a priest would, instead of saying "the Mass is ended, go in peace," say "the Mass is never ended..." (a worthy thought, I suppose, but still) "...continue to live it."

I guess my question is:

Why is a "signature" needed?

We're not talking about haute couture or designer jeans here. We're talking about something so awesome—the Holy Sacrifice—that no "trademark" need be added. Why, then, do some priests feel the need to put their own "stamp" on what is already perfect?

Anybody? Am I missing something here?