Which Nginx server actually respond with image data?

Question

I have two servers with Nginx running on both.

On first server I'm enabling proxy_pass to all (png|jpg|gif) and so on to second server.

So my question is - Which server actually respond with image data?

1) Second ->(bytes)-> First ->(bytes)-> Client
or
2) Second ->(bytes)-> Client

I have a serious restriction in traffic on my first server and want second server which has not this restrictions to respond with all images.

Can I do it like I do, or I need to actually use second server in all img tags?

Thank you and have a nice day!

Answer 1

Since you use first server as a proxy between client and second server, then the answer of course is (1), the first server responds to client.