Iphone 12 pro max

This is not a technical support question. If you hold the phone tightly as it would appear you are, you may have the issue you're having. Otherwise, the phone has flat edges, like iPhone 5 did. Put your phone in a case with softer sides, which will be helpful. Or, if you simply don't like the design of the phone, it's not going to be redesigned for you, so return it and get another phone which you think will feel better in your hands.

Personally, I'm thrilled with the new design. My iphone 5 was may favorite design of all time and returning to the flat edge design is to me fantastic.

Something like this might help you a lot:

This is the Spigen Quartz Hybrid on my iPhone 12 Pro Max. The sides are soft and grippy and the back is tempered glass and won't scratch. $19.99 at Amazon.com

It would appear that you are holding the device entirely too tight. That is what is causing the pressure marks that you have photographed. If you purchased from Apple, you have 14 days from the date of purchase to return the device to Apple for a full refund if you are unhappy with the device.