To me this sounds like an orienteering schema - where a child expresses an interest in positioning themselves or other objects in different places or positions. Some examples are wanting to be upside down or on their side. Sounds like he’s just exploring his environment and finding the angles of the book and how different they look to him fascinating 😊 I’d say totally typical!
@Becky thank you this is reassuring
You’re so welcome!
Lool 😩🤣