A. If you want to confirm the device has OTG function:
-Use of USB OTG allows those devices to switch back and forth between the roles of host and device.
-A mobile phone may read from removable media as the host device, but present itself as a USB Mass Storage Device when connected to a host computer. （src: Wikipedia）
B. If you want to confirm the USB C device has video out function though USB-C port.
Verify to the type of logo printed beside the interface:
(1) USB 3.1 Gen 1 + Display, with video display function, and theoretical bandwidth with a maximum transfer rate of up to 5Gb/s.
(2) USB 3.1 Gen 2 + Display, with video display function, and theoretical bandwidth with a maximum transfer rate of up to 10Gb/s.
(3) Thunderbolt 3 connection technology combines PCI Express data transmission technology and DisplayPort display technology, which can simultaneously transmit data and video signals, providing up to 40Gbp / s bandwidth. (Normally, the icon next to the Thunderbolt 3 interface is only marked with a lightning symbol)
(4) Check the SPEC information on your device's official website. Confirm if the USB C port-specific saying it carries a video signal, or supply DP Alt mode.