Hi,
Just add the texture and apply it to the head:
Code:
neutral = viz.add('neutral.jpg')
happy = viz.add('happy.jpg')
head = viz.add('head.vzf')
head.texture(happy,'name of the geom you want to apply graphic to')
.
.
.
head.texture(neutral,'name of the geom you want to apply graphic to')
Did swapping the vzf heads not work either?