Several of the commonly available IR remote kits come with a multi-key remote, a sensor, and another LED which is sometimes mounted to a small circuit board or may be a separate component. Is this just an additional IR sender in case you don't want to use the hand-held pad?
Would be useful if you provide a link to an example.
Here's a link to one example. Remote keypad (which would be an emitter), in this case a receiver on the circuit board, and a separate LED.
That looks like a spare ir led for transmission. It is not listed in the items being sold, so you may not actually get it.