When zooming Instagram profile pictures, it's important to find the right balance between magnification and clarity. Zooming in too much can result in pixelation, while zooming in too low may not bring out the details you want.
Before you enlarge the picture, make sure that the profile picture already has a high enough resolution. A high-resolution image loses less quality when enlarged.
Use the familiar "instazoom" gesture on your smartphone. Place two fingers on the profile picture and spread them apart to enlarge the picture. Make sure to perform the gesture gently to avoid overstretching.