Why are there purple dots on my moto z play

[AC Question]

Today when I powered on my phone appeared on my moto z play on the top right corner of my phone and the bottom left corner of my phone

WHAT IS HAPPENING

 

[Tim1954]

Dial *#*#0*#*#* should test your LCD hardware... You can google secret codes for any device and do amazing tests. And brick your device too...