Looks like I figured this out.
Headers need to be set up as follows:
self.bweHeader = @"http://bigwatersedge.axiscam.net/view/snapshot.shtml?picturepath=/jpg/image.jpg?timestamp=";
self.bweImage = @"http://bigwatersedge.axiscam.net/jpg/image.jpg?timestamp=";
self.bweHost = @"bigwatersedge.axiscam.net";
NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:[self.bweImage stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]] cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:60.0];
[theRequest setHTTPMethod:@"GET"];
[theRequest addValue:self.bweHost forHTTPHeaderField:@"Host"];
[theRequest addValue:self.bweHeader forHTTPHeaderField:@"Referer"];
NSData *data = [NSURLConnection sendSynchronousRequest:theRequest returningResponse:&response error:&returnError];
NSImage *camImage = [[NSImage alloc] initWithData:data];
[self.imageView setImage:camImage];
[self.imageView setImageScaling:NSImageScaleProportionallyUpOrDown];