[Steven Zahm]

@ Corinne

It is not possible to use images from the Media Library when choosing to add an image to an entry. This is largely to support scalability. There are Connections powered directories with hundreds to hundreds of thousands of entries. Having images in the Media Library for these directories would make it nearly unusable and potently slow the entire site because WP stores quite a bit of metadata about the image in the same table where the posts and pages are saved.

Hope this helps!