It is an Ottonian manuscript. It <span>produced magnificent medieval illuminated manuscripts and it is about religion. They were a major art form of the time, and monasteries received direct sponsorship from emperors and bishops, having the best in equipment and talent available. The range of heavily illuminated texts was very largely restricted (unlike in the </span>Carolingian Renaissance) to the main liturgical books, with very few secular works being so treated.
The correct answer to this question is "curving the forms of certain objects, such as the bookshelf and ceiling, in order to create the 3-dimensional sphere of the mirror." In order to create space, escher created space by doing this. Thank you for posting your question. I hope this answer helped you. Let me know if you need more help.
