'One second, securing the line' when making card payments on the phone

Increasingly over the last few years, I've heard this from advisors when making payments over the phone. Are they triggering some sort of software that handles encryption of the line through DTLS/IPSec? Are they obfuscating keystrokes from the advisor? I'm curious!

advisor advisors card cybersecurity dtls encryption ipsec keystrokes making payments phone software sort