The picture shows how the screen buttons respond to the changer condition. As pictured, disc 4 is playing so its button is highlighted in a green color. Discs 1 and 3 are inserted in the player and you can press these buttons to select the coresponding disc. Discs 2, 5 and 6 are empty slots in the player. If you insert discs into the player for these solts, those buttons will be enabled like buttons 1 and 3 are.

Everything else is the same as before.