The book of Revelation promotes three types of genres:
These three different forms of writing styles/genres blend together into a cohesive unity thus forming a relatively distinct and multi nuanced literary composition.
John is not drafting this as he is seeing it. He shows reflection and intentionality with how he weaves the message of the Revelation. Again, John is writing into a contemporaneous Sitz im Leben i.e. a historical setting which involve local communities in Asia Minor that are going through or about to go through severe testing, trial and (from John's perspective) a testimony unto death! John wants to encourage them to be overcomers and utilizes the rich tapestry of this book to do so.