It’s such a silly joke. It’s not “omg hahaha look at how short he is” it’s “omg hahaha that shield does look like a guitar pick now!” and then you imagine him 3cm tall and it’s just an absurd image

I think Dinklage would be more offended at people tiptoeing around his height like it’s a sensitive and embarrassing matter.

He knows he’s short, we know he’s short. He’s not insecure he jokes all the time. It would be offensive if the joke was making fun at his appearance / height. It was more focused on the shield.