Looking at your profile, I get the sense you are trolling :) but I have a bad time imagining the need for the elasticity of lambda for those single-user actions.
I'm not sure whether it's what they meant, but I could see the "admin" cms portion being hosted on lambda.
You'd load a static editor page, write your content, and then post it to a lambda endpoint. That lambda would then generate static pages for your content and push it to s3 or wherever.