Hamlet here distinguishes the grief he feels from all acts of mourning.
'Tis not alone my inky cloak, good mother,
Nor customary suits of solemn black,
Nor windy suspiration of forced breath,
No, nor the fruitful river in the eye,
These symptoms do make oneseem depressed, but they are exterior displays that any man could fake. By contrast, the grief Hamlet truly bears is the real source of all these behaviors.
Hamlet is implicitly chastising his mother for her superficiality, evidenced in her brief mourning for King Hamlet and quick remarriage to Claudius. He shuns her contrived image throughout the play, and especially in the closet scene (3.4). As far as we can tell, he never believes that his mother fully or appropriately mourns his father’s loss
