The detailed realism, which is clearly due to an evident pedagogical intention behind the painting, is the overriding value in the representation of this theme. The traces of blood on the knife and the towel, or the pointed tip of a bone at the end of St. Joseph’s staff, are details that denote a peculiar feeling, perhaps reflecting a certain southern European sensitivity, and which would therefore be very rarely found in northern European painting. The wrinkled faces and the gazes directed towards the Child Jesus, whose body is turned towards the observer with an almost pathetic expression of alienation from the scene, give us the real dimension of the sacrifice, clearly symbolised by the knife, which is also represented diagonally, as a cutting element.
In a composition that is dominated by the vertical lines of the background, accentuated by the brocade that spreads over a marbled altar, the figures are arranged in such a way as to form an essential diagonal line. The figure of St. Joseph, which is too voluminous, seems to result from an attempt to balance the composition and the need to fill in the space, because of the difficulty in suggesting its depth. It is natural that an engraving by the Master E. S. should have inspired the representation of this figure, and his hood depicted in profile adopts a somewhat capricious form. The attention to the tiniest detail is visible in the transcription of the correctly drawn brocade, in the beautiful frieze of precious stones of the figure placed behind the Virgin, and also in the high quality of the sculptures and the decorative architectural elements in the background.
In the figure of the high priest, in his collar at the height of his chest, the inscription VASCO has been identified, which, although it does not allow for any positive or definitive conclusion regarding the complex question of the authorship of this group of paintings taken from an altarpiece, is already highly suggestive.