The court was told that when the mother called Harris "a disgusting creature", he gestured at her daughter and whispered "she liked it".
On an earlier visit to New Zealand in 1970, he allegedly placed his hands under the dress of a teenage girl while dancing with her.
"The experience shows another step in the pattern of Mr Harris' behaviour ... He was targeting people who were in awe of him, he pushed the boundaries even in a public place, a dance floor. He knew he could get away with it," said Wass.
He was "an immensely talented man" who possessed a "kind side" that charmed audiences.
But she said his fame gave him the opportunity to carry out "brazen" indecent assaults, often when others were present.
The Crown contended Harris believed his popularity made him "untouchable".
"Concealed behind this charming and amicable children's entertainer, lay a man who exploited the very children who were drawn to him.
"There is a Jekyll and Hyde nature to Rolf Harris."
A large group of supporters, including his wife Alwen, was in court.
The trial continues.
