It would have been funnier if there was another panel where Madoka asks: "Homura, did your breasts get bigger?" Then Homura proceeds to be unamused.
Homura-chan, did your eyes get bigger?Yes, all the better I can hear you with, Madoka.Yes, all the better...Yes, all the better I can see you with, Madoka.Homura-chan, did your ears get bigger?Homura-chan, did your mouth get bigger?