Every time I looked it was there. My super awesome mod powers tell me that the image was never removed unless it was removed by you and then replaced by you or a moderator removed it in the three-minute timeframe immediately after you originally posted it so that the removal didn't register in the edit history. But it's extremely unlikely that a moderator would be there right when you posted a perfectly appropriate image and removed it within three minutes and then disappeared without giving you an explanation why.
The likeliest explanation is that it's a png file, and they like to not show up to some people. If you edit your post, you'll see the link is still there.