Earlier quoted context omitted.
Now it is recommended to use width and height attributes on img elements. It will help to prevent viewport jumping and will support responsive aspect ratio resizing. https://www.youtube.com/watch?v=4-d_SoCHeWE
If you specify both a width and height, it's not going to be very responsive.
max-width: 100%;
height: auto;
What the other user is talking about is a new feature that FINALLY uses the attributes to preserve the ratio before the image starts loading.Kinda ridiculous that we had to wait 8 years of “responsive design” before they realized that this was always supposed to happen.