Wide-eyed, mouth agape, brows arching in conflicting directions, and a voice calibrated to a cartoonish pitch. These alone capture Aamir Khan’s last two performances. The characters could scarcely be more disparate, the settings poles apart, the films themselves worlds away. Yet Aamir’s tonal signature remains parochial. Whether embodying human disability in Laal Singh Chaddha or affirming that difference is no deficiency in Sitaare Zameen Par, his delivery borders on buffoonery, undermining the very humanity he intends to convey. Why this sudden critique of his performances? Why not. Recently, Sai Pallavi, in her Bollywood debut with the Aamir-backed Ek Din, confessed on his YouTube channel that perhaps she had been miscast , saying, “I think somebody else was meant to do this film.” It makes you wonder, the superstar, hailed as the “thinking Khan,” seems increasingly at odds with his own portrayals. The precision he demands from others often eludes him in his own embodiment.…