I can't really think of a case where a post's image isn't relevant to the associated discussion. Even if it's just a nonsense post with an unrelated image, knowing what the irrelevant image is about would help make sense of the discussion.
Not enough info is better than nothing. Because if it's nothing, you can't tell if the person who shared the image is lazy or decided the alt text wasn't necessary for this particular picture
The Best of World SF is undeniably an excellent sampler of voices from around the world, both of authors and of translators.
The editor comes off as maybe a bit self-centred? But I can't deny they have excellent taste and connections.