Some security inspection appliances and load balancers don't appreciate
something in the HTTP headers that is not a valid HTTP header. Furthermore,
the browser needs the Content-Type header to identify that the image is not
the PHP default of text/html

Some security inspection appliances and load balancers don't appreciate
something in the HTTP headers that is not a valid HTTP header. Furthermore,
the browser needs the Content-Type header to identify that the image is not
the PHP default of text/html