Had he been uncertain in his understanding of Chris's directions? Perhaps. Or maybe the Heirophant's direction of 'smash the eyes' was meant to include the mirror. In either case, now he understood why he was doing this.
"Yes, Heirophant," he says. Uncertainty would do him no good. His open palm, covered in eye gore, curls into a tight fist and the Taifa punches the glass -- once, twice -- once for each eye, shattering the mirror and leaving new little nicks on his hand. The smashing noise of his fists was followed by a quiet coda of tinkling as glass shards hit the floor.