Describe the bug
It appears that requests for .png images take seconds to complete.

Do note that next/image and the plugin are used out of the box i.e. no extra configuration such as loaders, domains, etc...
The original images are also <1MB.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://60e93905292d6a0007ab089a--admiring-saha-1bedaa.netlify.app/
2. Check network tab on console
3. Refresh the page
4. Observe that requests for images take seconds to complete

Expected behavior
Requests for images should not take seconds to complete.

Versions

• Next.js: 10.2.3
• plugin: Installed via automatic installation (v3.6.3 as of writing)

Supporting Info

You may find the example repo here
https://github.com/shaoyi1997/netlify-nextjs-issue-example

The screenshot below shows a sample of the network requests for images (taken on refresh):

You may also find the logs produced by the next_image function for the above requests below:

I believe this may be related to #435, but do correct me if I am missing out on any steps or if any config changes are required.

Thank you for your work!