don't get offended, the request was quite funny on first notice, atleast until I thought for minute how it could be useful :- )
Anyway, it's definitely not the same, exposure is inherently tied to creating images simulating camera, but email client is not.
If there's one thing (apart from great quality of renderer itself) that distinguishes Corona from competition at this point,
is the simplicity of integrating only necessary things and not overdoing it on robust gimmicks. Neat and minimal UI is one of those things.