The frontispiece to Eikon Basilike showed Charles I as a martyr, kneeling in prayer.
Little pearl - who was as greatly pleased with the gleaming armour as she had been with the glittering frontispiece of the house - spent some time looking into the polished mirror of the breastplate.
In fact, the famous frontispiece of the book, which is reproduced in your edition, although it is not altogether very clear.