My picture don't appear.....

[Chimpola]

I've listed quite a few items, all in the same way and for about half of them, my photo doesn't appear as a small icon when in a list with other people's stuff (am I making sense?). The photos are there but if a buyer is searching for e.g. Shoes size 5, they get a list with lots of different items, including mine but you have to click on my item in order to see the photo

What am I doing wrong or is it just a glitch?

Thanks

[Chimpola]

'Doesn't' appear