Icons are more than sacred pictures. Everything about them is theological. For example, they are always flat, flat so that we who inhabit the physical world will understand that the world of the spirit where Christ, His Mother, the angels, the saints, and the departed dwell, is a world of mystery which cannot be penetrated by our five senses. Customarily, Roman Catholicism has historically employed statues in its worship. The statues are life-like and three-dimensional. They seem to imitate the art of ancient Greece. Both arts are naturalistic. The Latins portray Christ, the Mother of God, the saints, even the angels, as if they were in a state of nature. This “naturalism” stems from the medieval idea that “grace perfects nature.” The person or persons are represented on the icon as deified. He or she is not a perfect human being, but much more: They are transfigured and glorified. They have a new and grace-filled humanity.
His comments on statues do not seem to be very negative; but in case he intends that his explanation about the flatness of icons should undermine statue use, I must say this: the conclusion, “statues are bad,” would not follow from the premise, “flatness reminds us that heaven cannot be penetrated by our five senses.” Moreover, a statue does nothing more or less with our five senses than an icon. In fact, if we
could contrast their suitability, it would seem that icons were somewhat worse than statues at reminding us of the glorified state; for icons constrain the Saints to two dimensions, and statues give them three, whereas the Saints, in reality, are far beyond all the dimensions we can portray them with.
Important to remember is the Latin theory of grace: It is created by God for man. Orthodoxy teaches, as we recall, that grace is uncreated, and impacts all creation. It is a mysterious extension of the Divine Nature. Orthodox iconography reflects this truth, even as Roman Catholic statues reflect its idea of grace.
Neither statues nor icons automatically reflect the Catholic or Orthodox doctrines of grace better or worse than the other. It would depend on how they were made, I suppose, but I really can’t see how they would do it even then. I do not see where he gets this idea.
In my experience, icons serve a very important place in Catholic worship. There is a section on icons in the Catechism, Catholic seminarians are given an icon of St. John Vianney, icons of the Sacred Heart and the Immaculate Heart, and the Divine Mercy, frequently adorn Catholic households, and icons are still made and venerated for Catholic saints. So we still have a major place for venerating icons, we just use statues too, and those have just as ancient a place in Catholic sacred imagery as icons do.
BTW, regarding the Catholic and Orthodox definitions of grace, grace, in both Catholicism and Orthodoxy, is uncreated, so this difference may be overstated. In Catholicism grace is divine favor, it is the life of God.