What PPSC actually asks for
A recent, professionally taken passport photo, at least 4.5 cm high by 3.5 cm wide, in JPG, coloured, on a white background. The CNIC front must be at least 5.4 by 8.6 cm and legible.
Those are PPSC's own words, from its Photograph Guidelines, and the page prints them in full with a link to the document. The Guidelines also rule out a covered face, caps and glasses, require you to look straight at the camera with a neutral expression, and say the photo must be only of you and not cut down from a larger picture. That last point is about using a snapshot of a group; cropping your own portrait to the required shape is exactly what the size rule expects.