It looks like the article attempts to embed images in different formats for different browsers, but the source images aren't of the image type they expect which results in broken images for some browsers.

    <picture>
        <source srcset="/img/r/p/500x600/8862.jpg.webp?v=1599098401" type="image/webp">
        <source srcset="/img/r/p/500x600/8862.jpg.avif?v=1599098401" type="image/avif">
        <source srcset="/img/r/p/500x600/8862.jpg?v=1599098401" type="image/jpeg">
        <img loading="lazy" src="/img/r/p/500x600/8862.jpg?v=1599098401" alt="Medieval Castle Latrine" class="in_text_image" width="500" height="375"/>
    </picture>

Firefox and Google Chrome both select the image with the image/webp content type, and those URLs do appear to be WebP images.

Safari selects the images with the image/jpeg content type, but those URLs appear to point to AVIF images (i.e., image data encoded using AV1 and stored in an HEIF container). AVIF is only supported by Google Chrome. This results in the images appearing as broken placeholders in Safari.

Also didn't work for me on iPhone/Safari.

They don‘t load on iPhone.