[zepolud]

I don't think you understood the process--there is no 2) post to exchange a shared secret, as it is derived from his private key and the already known to him public key of WL.

There is also no prior need to contact WL--this is the whole point of the scheme. All this is public so NSA is supposed to be well aware of WL monitoring all these messages. That's why he would be encoding using wordlengths modulo 2 (see my post below) so they are statistically indistinguishable from normal text. NSA would not be able to detect suspicions activity without having the WL private key.

Also, there is no need to raise undue suspicion by using untypical photo sizes as he can publish as many and as different files (e.g. video, music, etc.) as he requires once the harder process of establishing channel of communication with WL has already been accomplished.