This was commissioned for an emperor and contains parts of the Liturgy of the Hours: prayers that Catholic religious do throughout the day. But it's not uncommo

This was commissioned for an emperor and contains parts of the Liturgy of the Hours: prayers that Catholic religious do throughout the day. But it's not uncommon for lay people to partake in those, either doing the full version or some abridged version. It's not impossible to imagine the emperor wanting his fancy version of this (whether to earnestly pray along or just to appear pious, we can't know).