skjian,
This booster circuit uses the similar principle as a voltage multiplier by means of 3 diodes.
There is a big problem here. 1N4148 is a signal diode. Using them as power diodes will "fry"them. This had to be stupid person who designed this. Perhaps he/she never had tested it before. He/she probably worked the 10V or higher, based on simulation.
One more comment. This is far too complicated circuit to use for boosting voltage. You can make a much simpler one using generic voltage multiplier.
There are many examples on the Internet.