In an Arduino sketch for my M5Stack Atom Matrix, I used the following code snippet,
that Microsoft CoPilot presented me to get the MAC address of the Atom Matrix:

uint64_t chipid = ESP.getEfuseMac(); // The chip ID is essentially the MAC address 
  Serial.printf( "\nESP32 Chip ID = %04X%08X\n", (uint16_t)(chipid>>32), (uint32_t)chipid);

The result of this code is: "ESP32 Chip ID = 90E08008B764".

Also

byte mac[6];
WiFi.macAddress(mac)

results in: 90E0808B764,

However, M5Stack M5Burner app reports the following MAC address: "64b70880e090".

Both values are a "mirror" of each other. How come?
Has it to do with "little endian" versus "big endian"?