First it depends what such call returns, is it html code with encoded image, raw jpeg or something.
Check 'programmer console/options/view' in your browser what does it do after going to this site, or use http debug tool/spy like Fiddler to get all needed info, as it may require to use some specific http headers to force some behavior. If you would need to get that image asynchronously best would be custom http handing code with network commands. If you would have any problems let us know.