I don't believe there's a pose player. The poses for Sims 4 are tied to a trait, like how the sims move and pose due to what their traits are.
So say you have the pose saved to the lazy trait, you want to play that trait with your sim and set the clockspeed slower with the cheat code bar. There are tutorials on how to do this if you google them.
But so far there is no pose player for Sims 4 yet.