God had the book in His right hand. The book contained the full and complete word of God to man. We must keep in mind that seals upon documents are not the documents themselves. A seal upon a document simply identifies and verifies the authority behind the document. The document is here.
Seals establish the authority behind the document.
In this case, the seals upon the scroll certify that the complete and full word of God is authentic and genuine. God does not think as humans. His memorials of memorable events have always been different than man would create. The Passover, the Sabbath, and the Lord's Supper are examples of God's different ways. The seals upon God's word are likewise different.