Why is this power cable sometimes polarized and sometimes not?

TECH-X 4 Feet 2-pin Universal Replacement AC Power Cord Cable 2 slot power cord 2 USB-A Gen 1 with PowerShare 3 DisplayPort 4 HDMI Security lock slot , 90W power delivery to Dell 20 power hot slot The 2 pin power cord provide long-lasting electric power transmission and heat-resistant Heavy duty 20AWG gauge cord, powerful and safe for power supply ▷

2 nvme slot motherboard 2 Prong Polarized-Power-Cord for Vizio-LED-TV Smart-HDTV E-M-Series and Others 2 Slot Adapter-AC-Wall-Cable: IEC-60320 IEC320 C7 24 sold Color :