It's low and it's square and it's RED. Red is the color of Mars, of war and of blood. The form of the incense burner on the altar is also pagan. Fire, of course, is also dedicated to Mars. The unrestrained worship of Mars and other warlike gods is considered dangerous even by pagans - - sorta like playing with fire.
I am acquainted with Classical pagan forms from my education in Classics, and contemporary ones from knowing some Wiccans (the ones I know are actually quite peaceful and inoffensive, albeit sadly misguided, but not all Wiccans are peaceful and they are the first to tell you so. These folks are more afraid of the bad pagans than most Christians are -- they know more about them.)
But the incorporation of this into a Catholic cathedral is little short of heresy. It tells me a whole lot more about this Mahoney character than I really wanted to know.