I just wrote a question before this one and had trouble uploading a screenshot. The drop your image dialog throws no warning or error, but after uploading it won't show.
I also noticed that other questions won't load their images. Could this be some issue with imgur or similar?
When opening the image in a separate tab, Chrome gives a "too many redirects" error:
This might be linked to Avatars aren't loading, with a status 301 (permanently moved) response