 Throughout the movie everyone wears the same clothing (or some  variation of the same clothing). All of the clothing is also from  the 1970s. Director Wes Anderson (qv) did this intentionally so  that it would appear that the Tenenbaums are trapped in the era of  their heyday while time moves on (the gravestone at the end reads  2001). Much of the setting, including the use of gypsy cabs and  Green Line buses, are also in keeping with this theme.