I've uploaded the image to the gallery, since subscribing. The problem is I can only see it when I log out! Apparently others can view it anytime.
You can see it anytime you want. It is just that if you access it through the "Latest Gallery Photos" link it takes you to the New Media sort. Once you have looked at it, it isn't new any more, so it doesn't show up on that sort!
Click on the Gallery Link at the top, and then Your Media. Alternatively, you can click on the particular sub-gallery (Standard Gallery or ??) you uploaded to.
The uploader includes an automatic re-sizer, which can be finicky. I prefer to do the re-sizing myself first. I find that colour images resized down to 800 pixels on the longest dimension work well. Black and white images resized down to 1200 pixels on the longest dimension work well.
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