Anyone remember MHL? A bunch of phones supported it. Absolutely fucking cursed standard.
USB Micro-B on one side, HDMI on the other. But Micro-B doesn't have enough pins to transmit a HDMI signal, so despite having a HDMI connector on the other end, it didn't actually transfer compliant HDMI. You needed a TV with MHL support, or a converter dongle, to get a proper HDMI signal from it.