Hello, this is how icons are loaded: Material Icons
<span class="material-icons">shopping_cart</span>
https://fonts.google.com/icons
This is not the best practice, but unfortunately it is done in the classic theme before, if you do not like this display, then you can change each icon and add a hexadecimal character instead of the text inside the icon.
<span class="material-icons shopping_cart"></span>