It is an issue that can easily be avoided by not using a browser written by morons. Thus, it is a browser-specific issue.
Is there any browser not written by morons? I use Safari. The images load for me, but it's "written by morons" as it's the only major one that doesn't have a setting to reject downloads, which is essential if you want to avoid malware. I have it set to ask which folder to download any potential downloads, and I can click "cancel" rather than choosing a folder, but this isn't obvious at all.
I'd like to think that Vivaldi is good, but it's Chromium-based so it inherits a lot of Chrome issues, like deeming that pages use too much memory and blocking content to save memory despite the fact that browsing was smooth and there was no issue. That said, I don't think the HTTPS thing is one of them. How is one supposed to know that the image that is trying to load is the real image and not malware injected by a third party (this actually happens with malicious banner ads... one reason to use an adblocker)? Roadgeeks just don't like it because so many of our hobby sites never added SSL support, so it causes issues with embedding images to the forum. This is the type of thing where IE used to display the "display mixed content" error/warning/prompt.