srcset attribute not working when the image in srcset is already used in the page

Question

I don't know if this is the expected behaviour with the srcset attribute. But for some reason, it's not working for me.

So, I'm testing on windows and mac, srcset differentiates them by the pixel density. So 1x means lower (Windows) and 2x means higher (Mac)

But for some reason, even in Windows, it's showing the 2x image instead of 1x. This happens only for those images which have already been used in the page.

somewhere in the same file
<img src="already_used_image.jpg" >


<img
srcset="already_used_image.jpg 2x, normal_image.jpg 1x"
src="fallback_image.jpg"
>

I have checked the docs but couldn't find relevant info regarding this particular case.