Wow! That's actually pretty cool looking, it looks like speckled trouts back lettuce. Not sure what's wrong though.

This is definitely mites! Use a pesticide like neem oil spray or a 50/50 water and rubbing alcohol spray once a week to keep them at bay.

Definitely spider mites. Mine just did the same!!

I'm having this problem, too. Is it for sure mites? I just bought this a few days ago and missed the spotting on the top leaf. I checked the stem & leaves for any white webbing, but now I'm reading that not all mites show that way. I'm thinking of returning the plant if it is mites, but I'm hoping it might not be? Any advice would be much appreciated.

I consulted a couple of plant gurus and they both agree that it’s spider mites. At first I was skeptical because I didn’t see any webbing but they were both sure. I did end up seeing a tiny bit of webbing after a few days.