Voldemort has been lecturing him in that eerie, high voice for long enough now that Hermione's knees are a mass of soreness, and her still-wounded body aches all over. It seems he doesn't care so much that Malfoy might "want Hermione for himself', as Malfoy has allowed Voldemort to believe – no, what bothers Voldemort is the deceit, apparently. The omitting of the truth. The dishonesty of it all. Hermione wants to strangle the Dark Lord, who lounges on his self-appointed throne and waxes poetic on and on about how disappointed he is in Malfoy, his wonderfully promising young protégée.