If an LED via Vcc and a resistor is attached to the GPIO2 line and pulsed that LED will pulse but the onboard blue LED will NOT. BUT..... if the onboard blue LED pulses the LED on the GPIO2 line will pulse as well.
If an LED via Vcc and a resistor is attached to the GPIO2 line and pulsed that LED will pulse but the onboard blue LED will NOT. BUT..... if the onboard blue LED pulses the LED on the GPIO2 line will pulse as well.