Read about this artwork is a button, which behavs like a link. It should be replaced with proper element due to accessibility issues.
Thanks for surfacing this. You're right, that callout is a button element but the button element is wrapped within an <a> link tag (with the URL in the href), so I believe it's fine from an accessibility standpoint.
Closing this out but feel free to re-open if you think there's something I'm missing.
I see now. But I couldn't even think It could be done so. According to HTML standard interactive elements like buttons or inputs shouldn't be a child of an <a> element. Look at "Content Model" section and the last example block of Section 4.5.1 The a Element. So it should be fixed and replaced with a <span> or other suitable element.
Agreed - thanks for looking into that!