The greater picture reason behind the naming and renaming "Mike the Frog" inside the PHP code block?

I was watching the video with Hampton in which he assigns and reassigns the name of the website mascot "Mike the Frog" 3 different times:

<?php
$name = "Mike";
$full_name = "Mike the Frog";
$name = $full name;
?>

This seemed unnecessary and excessive...why not just name the variable name that we want once vs. this shenanigans? I get that he was trying to explain that PHP reads from the top downward, but I feel like this is a strange way to explain that concept...is there a time when in PHP we'll need to assign and reassign something like this over and over? I feel like perhaps there's a greater picture meaning behind what he did that I didn't see from his video...maybe not, but I thought it's worth an ask.