In chapter four, even though Yahuah the Son introduced John into the scene of the throne of Yahuah the Father, the Son is almost invisible during the worship bit.
In chapter five, however, the focus shifts to Yahuah the Son when He is worshiped and acknowledged separately in the presence of Yahuah the Father, after he took the scroll from the right hand of the Father.
Then, in the final words of worship of verse 13, both are acknowledged and worshiped ("to the One who sits on the throne and to the Lamb").
Reply from Watchman Bob: Interesting insight. The Son receives equal worship with the Father - something that can be said of no other human or "god" who has ever lived.