The options specified by #+ keywords are set during asynchronous export whereas those specified by the #+BIND: method aren't. In the following example, org-latex-image-default-width is set to .25\linewidth only in synchronous export whereas the author is set regardless of the type of export.
--8<---------------cut here---------------start------------->8--- #+AUTHOR: myself #+BIND: org-latex-image-default-width ".25\\linewidth" * 1st heading [[file:some_picture.png]] --8<---------------cut here---------------end--------------->8--- I think both the #+KEYWORD: and #+BIND: should have the same behaviour whereas one is using async export or not. Julien.