OK, here's what you do:
(1) go to your original FS post and click on
MODIFY(2) erase all the links to those tiny pics
(3) click on "
select and insert an image from your gallery" (it is right under the text box)
(4) your Gallery will pop up. Select a pic from it.
(5) repeat steps 3 and 4 till your ad contains all your pics.
That should do it.