In Grande Odalisque, Ingres emphasizes which form, considered the most beautiful in art at the time?

The answer is the "S Curve"

Explanation:

The "S Curve" is a form of art with its origins in Greek and Roman culture where a female body is presented in a serpentine posture which resembles the letter "S".

The word Odalisque is considered to signify a female concubine in a traditional Harem setting. The Grande Odalisque is the masterwork of famed artist Ingres who constructed an oil painting of a concubine who is postured to resemble an "S" curve which was considered by Ingres as the most beautiful and exotic form of art.