That gesture needs a device that supports multitouch. Not all of them are compatible (I don't know about your specific device).
A good way to check if your device supports multitouch is trying the "two fingers swipe gestures" in a book.
Two fingers swipe to left / right will show you the TOC and bookmarks if your device is compatible. They won't do that if the device is single touch (probably the gesture will be recognized as a single finger swipe, moving you to the previous/next page on the book).
For single touch devices the way to do a screenshot is a "loooong diagonal swipe". That should work for multitouch devices too
