what is meant by grandma says to young man that he did good ,in the last scene and when she pours sand on herself?

This play is clearly about the death of Grandma—and is dedicated to Albee's grandmother—but he writes a drama that defamiliarizes the audience with the typical scripts of death. Mommy, who most dutifully speaks the language of funerals and death—"It pays to do things well," she says of the funeral—leaves before the end of the play, and the audience is left with an affectionate and kindhearted tableau between a handsome young man and an old woman at the end of her life. In this way, Albee seeks to re-stage the typical funeral as a more ambiguous scene. Albee's play is his own version of how a funeral might go, layered on top of Mommy's more traditional (if absurd) conception of death and funerals.