In the room description what requirements are necessary to make an object appear in the rooms look at script, especially if you are toggling visibility of specific objects.
The "You can see" message includes all objects that are in the room, visible, and not scenery when it is displayed. If any of those objects don't have the "hidechildren" attribute and are either transparent or open, their children are shown too.
Note that if you make an object visible after that line has been displayed, it won't change. It will carry on showing the objects that were visible when the player entered the room or looked around.