The site is HTTPS—if you’re talking about the mixed content warning, I’m hotlinking all the images so it’s unfortunately unavoidable.

Ah, you're right. I just looked at Chrome's URL bar, and saw "not secure". Should've looked more closely.

You're right about the mixed content warning being unavoidable.

You could cache the images and serve them on your own domain. I’m pretty sure this is Reddit handles thumbnails in their lists.

I'll echo what they're saying. I'm not getting SSL either.

One of the top post images is 404ing so it displays a little broken file icon instead.

Yeah, that page has very explicitly set an og:image that doesn’t exist. (It looks like it was intended specifically for that page, too.) It’s unfortunate but I’m afraid there’s not much I can do about it short of hard-coding a special case for that one post.

Is there a reason that site needs to be HTTPS? It doesn't have any user login feature, and it's read-only. So what are the arguments for making it HTTPS?

To prevent a man in the middle attack. There's a possibility that a hacker could inject malicious scripts into the payload, or even completely change the content of the website that you think you are viewing.

HTTPS stops the content being modified on its way to you. Some less than scrupulous ISPs have injected their own ads into pages, which would be prevented with SSL.

Someone sitting between you and the site (Wifi router? ISP?) could potentially inject their own scripts.

Thanks. All pretty valid arguments, and probably enough to outweigh any potential slight performance/latency issue.