HDMI standard developers this week, cheered growing army of devices owners with USB-C ports can be connected to the future monitors and TVs with HDMI interface without the use of adapters.
However, there are some limitations. Firstly, for the so-called "alternative mode" support the direct connection of a monitor with a HDMI to USB-C port must support the mobile device itself.
Secondly, through the "straight cable" can transmit a signal compliant with HDMI 1.4b, while the market already have devices supporting more modern HDMI 2.2. That is, transfer the video to 4K resolution will, but the HDR will not be maintained.
The new cable will not work with older devices, the port is equipped with a USB-C without the support of the "alternative mode". To implement a "direct" connection, you will need to wait until the market compatible devices.