The thing about a proposal is it should fit with not only your character but your partner's as well. Obviously the two are very nerdy, they both love Portal (I mean.. I can't see someone who DOESN'T like portal getting through those chambers), and thus his proposal was perfect for them.
I think proposals reflect the relationship, and if you know your loved one as well as you should, you can come up with the perfect way of asking, in a way that you'll both remember forever.
Not every proposal would fit for every relationship, while one method would be awe-inspiring to some it may be downright insulting for someone else.
~Plystire
A rose is only a rose until it is held and cherished -- then it becomes a treasure.