I went to watch it because of your comment. Wow does it ever. I'm guessing the cracks are caused ultimately by water freezing in the winder and melting in the summer, and not by a giant super volcano ready to explode.
That being said, Jenny Lake is a great hike to go on. I live about 1.5 hours away, and and gone twice. It is a hike around the lake with some great views of the surrounding valley.
That last line does change the vibe from "a cliff develops a new crack and a tourist attraction is closed" to "omg Yellowstone supervolcano Armageddon!!1"
Hey, I would like to get in touch with you regarding an older comment of yours and ask some questions. If its ok with you ping me at qqtolene@gmail.com