@prometheuscomic: Images resized by WP loose some color and sharpness. Unfortunately, after some changes made last August, that also includes images inserted in real size (such as the example you link to) as long as their code includes the dimensions declarations. So the solution is to switch your post to html and remove the width and height commands from the image code.
Thank you, all. I’m embarrassed to admit this, but I think the problem was that I clicked on something and it made everything smaller (like when you hit control+minus). I hit control plus and now the image is like it used to be.
Put this problem down to pilot error!