This is a primary characteristic: the alleged Obama document appears entirely digital, while the Decosta document is obviously a scan of a physical document.
As Hawaii issues only hard copies, not electronic, QED the Obama is a forgery.
Also, Hawaii always stamps--the Obama specimen has no stamp, hence is not a legitimate certificate.
To stop inconvenient inquiries which would uncover a deal-breaker, a deniable placeholder was created.
Very nice.