It is probably the same as many other low resource devices (e.g. phones, most tablets, and many inexpensive compact cameras) where the device's processor is not powerful enough and the data channel (buffer and storage) aren't fast enough to handle the large amount of data from a large number of high resolution images taken in a very short period of time. When used in a "burst mode", these devices usually switch to what is really a slow frame rate video mode and save the individual video resolution frames as JPEGs rather than compiling them into a video steam.