[SpicyLemonZest]

The author's missing the fundamental tradeoff here. "Alt text is notoriously difficult to get right and heavily dependent on context" precisely because alt text is an assistive technology; you can't rely on context-insensitive tools or your intuition as a sighted person who sees the entire website at a glance to understand whether some fun tweak to the alt text will make things harder for those who are relying on it. Unless you have the resources to focus group it, I don't know how you could possibly be confident that adding a touch of whimsy to your accessible design isn't causing problems.