"And hawksbill sea turtles? Under ultraviolet light, they turn into glow-in-the-dark, underwater Christmas decorations, with both greens and reds arranged in overlapping chevrons."
By comparing the animals to Christmas lights, it paints a vivid picture of what the animals look like under UV light, and how colorful they become, and hints at how sea turtles see each other – which would be very different from what we normally think of how turtles look like. It's unfortunate that the article doesn't actually show a picture of a sea turtle under UV light, so it's a bit harder for the reader to truly appreciate the comparison. But, they do have some pictures of a comparison of opossums under UV light and under regular light. I think it weakens the article a bit, but also space is a premium, and maybe pictures of turtles under UV light just aren't available.