Noor Basra, 15, and Noor Sheza, 16, were filmed running and smiling in rain in traditional dress outside their house in Chilas, in the northern region of Gilgit.
The six-month-old footage was circulated via mobile phones and it caused outrage in the conservative Pakistani town, local news reports said.
Last Sunday the girls were shot alongside their mother in their home by five gunmen. The local police are investigating whether the attack was arranged by the girls' step-brother Khutore, who wanted to 'restore the family's honour'.
Last year, four women are believed to have been killed by tribal elders for dancing and singing with men at a wedding party in the remote north-western Pakistan.
A tribal council of clerics - known as a Jirga - had condemned the women to death for ‘fornication' and staining their families' names.
According to women's rights group, the Aurat Foundation, about 1,000 'honour' killings take place in Pakistan every year.