I put an item on e-bay and included the free picture.  When I went in
to look at it being listed in it's category - there was no picture,
just the icon of a camera.  When I clicked on title, the picture was
there, but I know from experience that chances of people looking are
higher if they can see a pic. I Tried different file sizes, shapes,
extensions
and no joy!  My husband listed an item using a picture from the same
camera.  What have I done wrong?  I use an Apple 9.0 if that's any
use?

Why not ask your husband to upload your stuff; watch what he does; and
see if he has any better luck?

It's hard to tell 'what you have done wrong' without knowing precisely
what you have done.

Maybe you haven't done anything and it's just a quirk in ebay ...

Or maybe if you watch your husband, you will spot the problem (if
there is one) for yourself.

Good luck!

Having the thumbnail picture show up in the category listings is an
extra feature called Gallery

For why you get the camera icon see
http://pages.ebay.com/help/sell/camera.html

For information on gallery see
http://pages.ebay.com/help/sell/gallery.html

(Or equivalent pages in your own country's Ebay)

Owain

Exactly what Owain said: the free picture is the one included in the
page itself, not on the listing in the category. If you want this one,
you have to pay a little extra. I must say, from my own experience,
that this little extra pays pack.