This site beggars belief! After spending 30 mins in a loop trying to get a simple picture in my advert, I come to the discussions section to raise the difficulties of posting a picture as an issue (again!) and as soon as I press the paragraph button, my post is accepted before even being started! - hence the blank post above.
Niscars, the chances are your picture file was too big. The maximum size is 1MG. Try resizing your image and you should find it works.
No, it wasn't that, as having checked previous posts to see what the problems were, I resized them to under 1MG. The pictures showed up in the preview but I pressed the submit button for 10 or 15 times but it just kept looping back to the same place.
On a related point, is there a reason why 3 copies of the advert are shown in the preview?