Image lightbox "download" link pointing to S3 bucket not CDN

Noticed that when an image lightbox pops up, there are two options: “download” and “original image”

When someone clicks “download” the image is downloaded straight from the S3/object storage bucket. When someone clicks “original image” the same image is opened in the browser off the CDN.

Just wondering if this is the expected behaviour? If so, is there a way to disable the “download” link so people aren’t hitting the expensive S3 storage and using the CDN instead, or change the “download” link to it points at the original uploaded file on the CDN instead?