She just can't convey as much emotion as singers like Rihanna and Katy Perry, but she does convey emotion. Now Rihanna, she sounded numb when she recorded Numb, you can tell she felt every word of Love the Way You Way Part II, and Love Without Tragedy / Mother Mary just screams emotion. With Katy Perry, you can feel her depression in songs like Thinking of You and A Cup of Coffee. Beyonce does have songs that show emotion like Start Over on 4, but her other songs that are supposed to show emotion like Halo came across as coldly manufactured. The vocals were there, but the emotion wasn't.