next/image does not work with assetPrefix

What version of Next.js are you using?

10.0.5

What version of Node.js are you using?

14.5.0

What browser are you using?

Chrome 87

What operating system are you using?

macOS

How are you deploying your application?

local production build

Describe the Bug

I dug through the docs and found only 1 CDN related config is assetPrefix, but assetPrefix only redirect js and css files to the CDN server. From what I saw in the next/image RFC, I think it’s reasonable to let next/image redirect local images to the CDN server.

After setting assetPrefix in the config file:

// next.config.js
module.exports = {
    assetPrefix: BUILD_ENV === 'local' ? '' : 'https://cdn.example.com'
}

and reference public image in <Image>

<Image src={'/assets/home/service-icon/labor.png'} alt='' />

results in a request to https://www.example.com/_next/image?url=%2Fassets%2Fhome%2Fservice-icon%2Flabor.png&w=828&q=75, not https://cdn.example.com/_next/image?url=%2Fassets%2Fhome%2Fservice-icon%2Flabor.png&w=828&q=75 as expected.

Expected Behavior

<Image> with local image path also applies the assetPrefix.

To Reproduce

Use both <Image> and assetPrefix.