A period in place of a comma

Yes, this movie was done in a very unconventional format. A lot of people probably turned it off after the first 5 minutes or so as they were bothered by it. However, if you stick with it to the end it all comes together in a strange sort of way. The very beginning sets the stage for what is to transpire throughout the film. I believe that this movie is in the Lessons Learned category. Shows what could happen when people are too revealing about themselves in today's high tech electronic media. How, in an instant, your reputation and lifestyle could be altered in such a way as to destroy you. In some instances it could lead to devastating circumstances and possibly end your life. Be prepared for a few shocking scenes unlike you have seen before. It was necessary, I believe, to show the reality of what probably happens in some of these instances.

I think the "how" clause is an objective clause of "show."
So, I was wondering how can the period before "How" be used even though the "how" clause become disconnected form the main clause.

Thank you in advance for your help.