Holbein was a great portrait painter but I wish to consider here one element of one particular painting.  His painting 'The Ambassadors' (1533) contains, in the middle of the frame, at the bottom, a strange distorted shape.  It is a 'momento mori' - a reminder of death to the two wealthy subjects of the painting.  The shape is anamorphic - it only reveals its form when viewed from a steep angle (i.e. from the side of the painting).  These distortions were used in the Stuart period, particularly by supporters of the King, who did not want to display their allegiance but nevertheless remain loyal - a portrait of Charles the First, distorted anamorphically only presents itself when a cylindrical prism is placed on it.

Holbein Investigation 1 (anamorphic distortion).

Investigate how bendy plastic mirrors, spoons and foil distort refelctions.  Draw a portrait of yourself in a#concave and convex mirrors.

Holbein Investigation 2

Using a cylinder of foil investigate creating portraits which only reveal themselves reflected in the cylinder.