What makes the Mona Lisa by da Vinci a cultural icon?

The aesthetic appreciation of Da Vinci's work would make
it a cultural icon.  The portrait is a study in painting technique with its technique in
both subject display, texture, foreground, and background, as well as symmetrical
designs.  It is something that has come to be appreciated as a landmark art work.  I
think that its vaulted viewing position at the Louvre has also helped to contribute to
its cultural icon status.  People go to the Louvre, in large part, to see the
Mona Lisa.   This is only enhanced by
its staging in bulletproof glass, impermeable to the elements that could wither
paintings like it, and to ensure that individuals who view it recognize that they are
standing in the presence of something iconic.  At the same time, the wealth that the
painting could generate on the open market continues to add to its iconic status.  I
also think that the fact that so many artists have referenced or parodied it do help to
feed the idea of a status that represents iconic.  Warhol's pop culture interpretation
of Da Vinci's work is only an example of this.  I think that one can get the full effect
of Da Vinci's work's iconic stature by surveying the internet to see what a search of
the work results.  The images seen are both representative of the legacy of the painting
and how it has become iconic in so many different ways.