In the first, are these the remains? Or beginnings...ice looks to be in thaw state...can see the temptation of the location... Is it an area that holds previous season's ice until the new begins forming?
Those pillars only form for about a month in the spring. In the winter, it is too cold and the water that forms them can't flow. You need the air at the roof of the cave to be above freezing while the floor is colder.
I had gone out there a few weeks before this photo was taken to see if the entrance had frozen up enough to climb. We had to slog through several miles of snow, but it was worth it. The entrance rappel was completely frozen up and there were these cool pillars all over the first 100 meters of passage. I decided to come back as soon as possible with a camera.
Unfortunately "as soon as possible" wasn't as soon as I would have liked. It wasn't until Memorial Day that we got back there. Most of the ice had melted, and these guys were only about 4' tall. I'm going to try to get back there again next spring and maybe bring better lighting. We only used headlamps and flashlights for this photo.