Seems specially designed to stir up western opinion
It's nothing to do with stirring up Western opinion.
There are all too frequent attacks against the Shia & Ahmadi communities too. Sikh & Hindu girls are regularly kidnapped, forcibly converted to Islam and married off to muslims.
Minority discrimination is institutionalised. There is a constitutional bar against non-Muslims becoming president or the prime minister of Pakistan. The Civil service and the armed forces do not promote non-Muslims beyond a certain level. Most non-muslims do menial work.
This brutality is just a continuation of that by the Muslim invaders of India who used terror and brutality to eradicate and convert by force non-muslims into muslims. Have a read of some Sikh & Hindu accounts about the atrocities carried out by the Mughal emperors. They are as gruesome as those by ISIS, such as boiling people alive.