Hey Amanda, firstly, welcome to the Guild, and to the Lite Challenge. Always love to see new faces in the challenges!
We have a 'thumbnail scraper' that shows all the challenges entries (it uses the Latest WIP tag to find them.) You can see
the current entries here. I think the scraper isn't finding your images because they're not hosted at the Guild. If you're struggling to figure out how the whole uploading/attachment thing works, there's a little
graphic here that might help. There are file size limitations, but I don't think you should have any issues with those (I think it's about 9 or 10Mb for a jpg).
Maybe you could post a new comment with the image uploaded to the Guild, and include the Latest WIP tag (there's a little button, 2nd from the right, on the comment box toolbar.) When it comes to voting time, most people rely on the thumbnail gallery to check out the maps. It'd be a shame if yours wasn't included, cos it's really nice work!
I hope this helps, but if it's making no sense, just holler.