Weird. I don't really have a good guess for that. I'm not saying this is definite, but leaves can curl in response to drought stress or root rot (leaves can't get water, show wilting). Granted, the curling is happening in a very strange way. Also, the leaf surface doesn't appear dehydrated.
But nevertheless, questions:
How are the roots?
How is the drainage from the media?
Is there good airflow to the roots in that glazed ceramic pot?
Is it possible the drainage hole is stopped up?
Diet of the plant?