There is an important difference between saying it is invalid html, and it is invalid amp markup. An img tag will work like normal. It just won't be a valid A

There is an important difference between saying it is invalid html, and it is invalid amp markup. An img tag will work like normal. It just won't be a valid AMP page any longer. >if your browser doesn't have JavaScript, it's not even going to know what any of those custom tags are, is it? It wouldn't. <noscript> tags are needed for that. But Javascript is a web standard, and this is the correct way to create new elements.