What sort of art is best for liturgical books?

Within the Church are present many disagreements between men and women of both faith and good will, and no small number of these revolve around the question of the proper appearance of liturgical items, especially the liturgical books. What is the best layout, page size or weight, binding, sense line, etc.

Another question of debate concerns the best kind of art to use within the rituals. Should a modern style be employed or an older style? If an older style, then from what particular era? Personally, I recommend we return to the style of the Middle Ages.

Take, for example, this drawing found in the Pontifical of Bishop William Durandus (d. 1296):

Rabbit riding a dog and hawking with a snail (@BIUSteGenevieve, Pontifical de Guillaume Durand, 14th c.) pic.twitter.com/G2iaGJbjJ2
— Damien Kempf (@DamienKempf) October 15, 2014

Or what about these rowing rats from the same book:

Rats Rowing (@BIUSteGenevieve, Pontifical de Guillaume Durand, 14th c.) pic.twitter.com/yiirWR9jlT
— Damien Kempf (@DamienKempf) October 15, 2014

What's that? You're not sure about the rats? How about this musical donkey-rooster hybrid:

Hybrid Donkey playing the lute (@BIUSteGenevieve, Pontifical de Guillaume Durand, 14th c.) pic.twitter.com/mA5hM5plan
— Damien Kempf (@DamienKempf) October 15, 2014

How could anyone disagree with the inclusion of such images? Not only are they artistically stunning, but they are also fun!