This image was loaded in with a regular "img src=" in HTML, using the statement below.
img src="https://upload.wikimedia.org/wikipedia/commons/thumb/8/8a/Fastly_logo.svg/1200px-Fastly_logo.svg.png"
This image was loaded in with a regular "img src=" in HTML, using the statement below.
img src="https://upload.wikimedia.org/wikipedia/commons/thumb/8/8a/Fastly_logo.svg/1200px-Fastly_logo.svg.png"
If a second image loads below, it was loaded via ESI, using the statement below.
esi:include src="/html/child_esi" onerror="continue"
If ESI was turned off in Fastly, the last image shouldn't have loaded.
If the ESI statement did not include onerror=continue, any problem while processing the ESI will error the VCL and the entire request will fail with some error.
When onerror=continue is included, any problem while processing the ESI will just exclude that child esi process and the parent HMTL will continue processing as normal (including other ESI statements that may appear latter in the HTML).