Kind of make you wonder if the company name is really Yogurtime - as in it's time to get Yogurt. That is, in the product photo their labeling for what should be "high" is off a bit depending on where you look. Obviously this has no effect on functionality but it is arguably amusing! 
In any case, those 4 yellow push-on jumper should be installed exactly as shown in photo. That is, this will be configured as "high" level triggering since when you flip the LED-switch to the "on" position it will send a "high" 12V DC signal to the relay module. You'd move the yellow push-on jumpers to the "low" position if you send Ground or Common to the input triggers to activate the respective relay.
