It looks like you have an AWS ELB load balancer with Sticky Sessions enabled. The Set-Cookie header essentially instructs Cloudflare to not cache the production URL. If you do not need the sticky session enabled it would probably be simplest to remove that config from the ELB. Failing that, you can set an Edge Cache TTL to override the bypass.
The URLs for the images you posted are stripped by the forum, I’ve copied them below.
The reason is that the responses have a Set-Cookie response header. Cloudflare will not by default cache such responses. Setting Edge Cache TTL for the path in question by using the “Cache Everything” setting in a Page Rule will cause Cloudflare to override the default behaviour.
The Page Rule should be configured to match the files you are referring to. You can use a Wildcard Match such as http://example.com/*.jpg to only target files ending in .jpg