Get it from iTunes. Seems like we cant upload more than 1 photo for each post. Maybe in full version we can. This app not really impress me, but since I'm waiting for Blooger app so I give a try, I think better to use email to post to Blogger. We also can make it as draft in outbox when no internet connection.
Normally I will blog from iPhone using special email address from flickr where we can upload and directly blog that image.