Artists have known for centuries that the average human adult body is made from parts that are in proportion to each other in predictable ways. If you draw your figures according to these ratios, your finished work will look more natural.
10. Emphasis- The redness of the lips, the darker cloud, and the fact that the glass is broken. I am not sure what the artists message is, but obviously, the three have some kind of meaning. The blue could be calmness, red, passion, broken glass, brokenness, dark cloud, depression.