Mechanical Engineering Jobs Salary Projects Software

What are some elements and principles of design, as well as reasons why this piece of art evokes sadness, fear and unhappiness?
The piece of art is “The Young Beggar” by Bartolome Murillo, http://upload.wikimedia.org/wikipedia/co…

This is for my textiles assignment, in my textbook i found about ten principles, are there 8 main ones or something? please help!!!!