From a wonderful blog I've recently discovered, Standing on My Head, by Father Dwight Longecker -
What you see pictured here is something called Catholic Worship. This is an ancient form of Christian worship that everyone thought was going to die out, but it is making a comeback.
Catholic worship is characterized by a God-centered act of devotion rather than a people centered act of fellowship. It is focussed on a corporate act of sacrifice offered by a priest rather than a corporate act of togetherness offered by a 'gathering leader'. Catholic worship focusses on a supernatural transaction that takes place between God and human beings. This transaction is called 'redemption' or 'salvation'. It was accomplished by the death of Jesus Christ on the cross two thousand years ago.
Read more here.