Sofa is a base game item that is locked until level 6 of the relevant career. Can be unlocked using cheats.

For these poses to work, you must have installed;

Andrew's Pose Player
Scumbumbo Teleport Any Sim

Place the teleportation knight statue (found in Buy Mode) in the middle of the sofa, facing forwards. Click on the statue and select 'Teleport Sim Here' then select the Sim you want to pose. Once the Sim is in place, open up the Sim menu, choose 'Pose by Pack', and select the pose pack. You can then choose from the 4 poses. The Sim should pose once you have exited the pose menu and unpaused the game.

The Sims in the photographs were made using skins, eyes, hair, eyebrows and eyelashes that were created by Seleng, Nightcrawler, S-Club, Bobur, Praline and Astonied, respectively. I do not claim to have created these items and all credit goes to the wonderful cc creators mentioned.