Actually since the last picture was taken a few weeks ago, the lake thawed, and now in the last few days has re-frozen.
So here are this week's cold pictures.
My guess is the melted area near the rocks is from the sunshine and above freezing weather both yesterday and today. Or maybe it's just today.
But the chill returned, and that sun is still very low in the sky. How about 8 more weeks of winter?