This is one of the most used modules in Cornerstone, since it is dealing with such an important part of the site - pictures. This module can display separtate images or the series if images called "galleries".
Remember that Calendar module records are very short. If you want a longer version of an event description you can always attach an article to a specific event. It can be a news article from your news feed or just a special article you wrote to make a story about what is gonna happen.