Rubin's vase

Rubin's vase 

An ambiguous drawing, which may be perceived either as a vase or as two human profiles facing each other (Fig. R14). See Blivet figure; Necker cube; Schroeder's staircase.
Fig. R14 Rubins vaseenlarge picture
Fig. R14 Rubin's vase
References in periodicals archive ?
France was first with prints employing the trickery, but it was subsequently developed in about 1915 by Danish psychologist Edgar Rubin and popularised as Rubin's Vase.