The meaning of the end scene in Portal

portal

In Portal, we are promised cake and a party at the end of our tests. However;

we soon discover that the cake is a lie.

Then, at the final scene;

there really is a cake (and my companion cube is waiting for me).

What's the meaning of this? Was GLADOS not deceiving me? Her comments seem to suggest that;

…she had the intention of killing me. Was the cake for us (player) and not for the character in the game?

Best Answer

This type of scene is called a "stinger".

http://en.wikipedia.org/wiki/Post-credits_scene#Post-credit_scenes_in_video_games

In this case, the use of the stinger is to demonstrate that GLaDOS is definitely

Still Alive (since the cores are waking up).

The fact that a cake happens to be nearby is just a joke.