Alignment tool that ensures correct fit, plus the fact that it covers the whole screen including the notch, leaving just a tiny gap for the speaker. You barely notice it’s there

Edit: correction, this is the link to the one that covers the notch. Apparently you can choose either option: Spigen Tempered Glass Screen Protector [GlasTR EZ FIT] designed for iPhone 13 Mini - Sensor Protection / 2 Pack https://www.amazon.com/dp/B095S3ZMZS/ref=cm_sw_r_cp_api_i_CB28FCC3RH572SFM1HVJ