Here is the seventh in the series of short videos by Denis McNamara, Professor on the faculty of the Liturgical Institute, Mundelein; his book is Catholic Church Architecture and the Spirit of the Liturgy. As usual, it is an excellent presentation.
In this one he focusses on sacred images. He describes how sacred images are a necessary part of the environment for the worship of God because they manifest those aspects of the liturgy that are present but not ordinarily visible. So they are there to give us a sense of the angels and saints in heaven participating in the heavenly liturgy.
In this video, the stylistic features of art that he describes are those of the iconographic tradition which portrays man fully redeemed. One point that he doesn’t address in this short presentation is the how the other authentic liturgical traditions, the gothic and the baroque, fullfill this function. I would argue that they do exactly what the iconographic styles does, but in a subtly different way. They are stylistically different and do not reveal man fully redeemed, but rather justified and at various stages on the path to heaven. But it is by revealing the path they direct our attention, via the imagination, to the destination point of that path, which is our heavenly destiny and so fulfulling their liturgical function. (If you are interested in a fuller discussion of this last point I direct you to section three of my book, the Way of Beauty.)