First I thought killing GLaDOS was part of the test and once you passed the final test and killed GLaDOS, she gets rebuilded, hence the new bulbs lighting up at the end of the game. But after reading WeeViL's post I came up with another theory:
Maybe the AI of GLaDOS is build with all the scanned brains of the test subjects which they backup in those white bulbs, making her knowledge very large and her character/personality very varying and weird, but still human in some aspects (humor, sarcasme, she talks about pain and how you broke her heart etc). All those individual brain backups form the AI that is called GLaDOS. Infact maybe when you finally reach the surface you are dead (note that if you die in the games made in the Half-Life universe the viewpoint falls down to the ground like a dead body and your view gets locked, just like a camera falling on the ground. Also exactly what happens at the end of Portal). But since your brain has been scanned and backed up your conscience continues to exist inside one the white bulbs, which you can see at end with the cake. So you do indeed get some cake?
Far fetched:
So since Aperture Science could (extract??) or backup brain scans this would also explain how the Combine recruited overwatch soldiers and stalkers, extracting the human braincontent and use their "dead" bodies as some sort of slaves without conscience. All of this using human technology! They are called the "Combine" for some reason, right?
All the knowledge gathered from the human brains could also have helped the Combine to conquer earth.
Maybe the AI of GLaDOS is build with all the scanned brains of the test subjects which they backup in those white bulbs, making her knowledge very large and her character/personality very varying and weird, but still human in some aspects (humor, sarcasme, she talks about pain and how you broke her heart etc). All those individual brain backups form the AI that is called GLaDOS. Infact maybe when you finally reach the surface you are dead (note that if you die in the games made in the Half-Life universe the viewpoint falls down to the ground like a dead body and your view gets locked, just like a camera falling on the ground. Also exactly what happens at the end of Portal). But since your brain has been scanned and backed up your conscience continues to exist inside one the white bulbs, which you can see at end with the cake. So you do indeed get some cake?
Far fetched:
So since Aperture Science could (extract??) or backup brain scans this would also explain how the Combine recruited overwatch soldiers and stalkers, extracting the human braincontent and use their "dead" bodies as some sort of slaves without conscience. All of this using human technology! They are called the "Combine" for some reason, right?
All the knowledge gathered from the human brains could also have helped the Combine to conquer earth.