I have two sites running on the same server. They use the same configuration (PHP version, WordPress settings, HTTPS, .htaccess rules etc.) While one site shows in Pingdom a wait time for images around 30 ms, the other shows a wait time 10 times higher for a similar sized JPG. Both sites are quite fast, but the first one is considerably faster. I have absolutely no clue what might cause this huge difference. Any ideas?