Arduino Wifi Shield R3 MAC Address mismatch

There is a MAC address attached to the back of my Arduino Wifi Shield. It says:
90-A2-DA-10-09-0A
However, when I get the Wifi Shield using the WiFi.macAddress() function, I get a different one:
78:C4:E:3:9F:B0
My code looks exactly like this:

#include <SPI.h>
#include <WiFi.h>
void setup() {
  Serial.begin(9600);      // initialize serial communication
  byte mac[6];
  WiFi.macAddress(mac);
  Serial.print("MAC address: ");
  Serial.print(mac[5], HEX);
  Serial.print(":");
  Serial.print(mac[4], HEX);
  Serial.print(":");
  Serial.print(mac[3], HEX);
  Serial.print(":");
  Serial.print(mac[2], HEX);
  Serial.print(":");
  Serial.print(mac[1], HEX);
  Serial.print(":");
  Serial.println(mac[0], HEX);                        // you're connected now, so print out the status
}


void loop() {
 
}

And my output is

MAC address: 78:C4:E:3:9F:B0

I really appreciate anyone who can help me or just discuss with me.
If you need more information, feel free to post here and I will supplement.
All those info I can think of:

  1. I am using a mac
  2. I am programming using the Arduino software IDE
  3. I am using Arduino Uno
    Thank you very much!

If you are network savvy, you can log in to your wireless router and look at the list of connected devices. That should show you the mac address the wifi shield is using.

I solve the problem. I verified that the tag at the back of the Wifi shield is cheating me. It is working now!
So what we learn from this is that DO NOT TRUST THE MAC ADDRESS GIVEN AT THE BACK OF THE ARDUINO WIFI SHIELD!
Thank you for your reply.