Sorry if this sounds alittle confusing (I am trying to get through the CloudFront documentation) but I have an app that is essentially downloading a bunch of images from S3.
Yes, you need to use the cloudfront distribution name instead of the bucket name. Since this is probably a download distribution, the name of the distribution starts typically with a 'd'. Generally, the full path to a cloudfront distribution looks like this: http://dxxxxxxx.cloudfront.net
I hope this helps?