Proportion is the relation between elements and a whole.
Symmetry is a vague sense of harmonious and beautiful proportion and balance.

Photos below illustrate how proportion and symmetry can  be used in in interior design.
These below are French antique gold platted cherubs:

And this one below is French antique garden iron bench:

 
From glancing at these two images, one may think that there is no connection between them ; usage, color, application all are different. But the trained eye will notice a balance and symmetry, and see a rhythm like music reflected in these two elements. The photos below of the similar elements lets us see their relationships.

In design it is all about balancing the visual volume of objects. Balance is created not just through shape and size, but also with consideration of color, pattern and texture. The shape and proportions of each piece of furniture and object must be in balance.  A room created with proportion and symmetry invites you to be in it, sit down and enjoy the well designed room.

Call or email me for expert advise: 203-858-6727

Hope to hear from you soon!

Nana