[Archive] ‘Image Inconsistencies: How and When Browsers Download Images’:https://csswizardry.com/2018/06/image-inconsistencies-how-and-when-browsers-download-images/ …
Nope. I never got a response to https://twitter.com/bz_moz/status/1006590909809549312 … There are various reasons loads might get lower priority. It's hard to say which of them might apply in a specific case without knowing the exact markup hostname details involved.