The soil in the pot looks pretty dry; taro likes damp soil that should never be allowed to dry out. And the pot looks a bit small for this plant.
It's interesting to read advice on some pages saying to give it dappled or partial shade, when the growing conditions I've seen have been huge fields with nothing around them to provide shade. So the north window might not be its happy place. I also see that they are supposed to lose their leaves inside if the temperature gets below 21 C degrees. If you keep your indoor temperature at 20 C degrees or lower during the winter, which my friends shame me into trying to do, that could be an issue too.
