It is not a fake lineup. That is the rotation from the starting lineup. They then shift into their attacking or offensive/defensive positions.
I had the same question as blue1234 after watching Sarina Koga receive serve in the back court and then proceed to kill the ball from Position 4 and not get called for a back court violation, and then on the next two plays she'd kill the ball from Position 4, and then she'd go back to serve! I imagine he's been watching Chatchu-on do the same thing. It sort of makes a mockery of a 'rotation'. That's why I call what they do before the serve goes off a 'fake lineup'.
To flesh it out a bit, if blue1234 is still wondering, a player doesn't have to physically be in position 2 on the court if the rotation says she's in rotation 2. She just has to be in front of whoever is in rotation 1, and to the right of whoever is in rotation #3. The players in rotation 2 and 3 could be back in position 5 if they wanted to be. Maybe.
I don't know if the rules specifically state that rotation 2 player has to also be in front of rotation 6 player but critical mass makes it happen because 3 has to be in front of 6 and to the right of 4, 4 to the left of 3 and in front of 5, and so on.
It's goofy