Yeah, these icy creations usually don´t last long. It can be still freezing in the shade but when they get hit by direct sunrays, they melt alway really fast. I was lucky I guess :) Hopefully, you will have another chance to visit the lake and take some cool shots there. The generation of my parents used to go to Balaton very often, it was a popular holiday destination for Czech and Slovak people during the communist regime.