Twenty Sixteen Site Logo Resolution

I am using the brand new Twenty Sixteen site logo upload feature that can be found inside the Customizer. The recommended image size for the site logo upload is given as 240×240, but when I upload an image that is sharp at 240×240, the resulting displayed logo at the top of the Twenty Sixteen (child of, but of course) site is soft and fuzzy. I have tested larger images, different file formats and different resolutions (72dpi vs 144dpi). But the resulting logo that Twenty Sixteen displays is clearly compressed and low res. Could someone please tip me off to what I am misunderstanding or doing wrong?