The painting of Mona Lisa is one of the most famous paintings in the world. Leonardo da Vinci painted it and it took 5 years to paint this. Over this time Mona Lisa may have changed from a happy woman to a sad woman or vice versa. This painting beautifully shows the concept of time and passage. The most important of which is the smile. Smile of Mona Lisa is the most iconic characteristic of the painting. It depicts how the Mona Lisa has changed over the years and her smile does not necessarily depict happiness or sadness. It is beautiful to note that how time can change the emotions of human and in this case also the emotion of a painting.