Yes, it's really simple. And if he meant sizing, "height" and "width" parameters still work in an img-tag:
<img src="img.png" height="100px">
(also the other parameter is set to "auto" automatically, at least in Firefox)
<img src="img.png" height="100px">
(also the other parameter is set to "auto" automatically, at least in Firefox)
the width will be set to match the aspect ratio but your browser will have to DL the image first. which probably doesn't matter unless you have content to the left/right of it, then it'll get bumped when the image loads. layout shift is a nasty thing.