Twig add attribute with value in a variable
I'm pretty sure the nested braces here are an error - inside a {{ }} expression, variables don't need to be enclosed again:

 {{ attributes.setAttribute('src', {{ rows[0].content }} ) }}


But for the real answer: This template isn't the culprit - the content is already rendered separately, passing through its own template which adds the comments.

See Get Views field value in Twig template, where the recommended way of getting at the unrendered field value is via the _entity object.