Head's Artwork Draws the People to the National Art Gallery

What is it about this artists work that makes it so interesting?

http://www.guardian.co.uk/artanddesign/2010/oct/28/clive-head-national-gallery-exhibition?CMP=EMCGT_291010&#

Will ye no think kindly on those who would be your friends! May the sun shine with your thoughts, today, and happiness grow in your heart! May you allow yourself some peace of mind.