Zooming in on Instagram profile photos usually requires additional tools or applications since Instagram doesn't provide native features to zoom in on profile photos directly. Here are steps you can follow:
Take a screenshot: Go to the profile whose picture you want to enlarge and open the profile picture. Take a screenshot of the image by pressing the required buttons on your device.
Crop image section: Go to your device's gallery and open the Screenshots folder. Select the screenshot of the profile picture. Use the built-in editing feature to crop the image so that only the profile picture is visible.
Image enlarger apps: Download an image enlarger app from the App Store. Look for apps that can increase image resolution. Upload the cropped profile picture to the app and use the image enhancement features to increase the resolution.