I think you're right-on about what art is, warch. The question, I guess, is this:
how much can a room with lights that go on and off challenge your perception? Sure, you can call it "challenging the notion of what is art" - but where do we draw the line?
Tony posted an IotD a while ago of
Wolfgang Flatz. I'll let you click the link and find out what all happened.
Is this still art? Would it be art if he hung himself from the crane and defecated onto the street below? Where is the line drawn? Sure, that challenges the institution of traditional art - but it's still just a guy shitting on the ground. Or a guy dropping a dead cow onto the ground. Or a room with some flashing lights.
Where is the line drawn?