This list is the key:
Here are a few things it might or not be capable of—but only one at a
- charging the device itself with 20V / 3A.
- charging a connected device with 20V / 3A.
- provide a DisplayPort 1.4 signal—you need a passive adapter. The icon mentioned is the DisplayPort logo so it's rightly used to clarify
a little the chaos USB C is. You still can't tell whether the port is
1.3 or 1.4 capable though.
- provide a HDMI 1.4b signal—you need a passive adapter. Perhaps the HDMI logo will be used, perhaps it won't.
- provide a Thunderbolt 3.0 signal which is PCI Express + DisplayPort 1.2 + USB 3.1 Gen 2 + USB Power delivery multiplexed into a signal served over the same connector using more expensive active cables.
Typically a lightning bolt is used but guess what? That's not a
- provide USB 3.1 Gen 2 aka 10 Gbit/s speed USB. Some motherboards will give you USB C connectors carrying USB 3.1 Gen 1 formerly known
as USB 3.0 signals at 5 Gbit/s just to have more variety because
clearly there is not enough of that.
- there's MHL,
A direct answer is there, in the third bullet point: the icon in question is the DisplayPort one. There's also a decent amount of extra commentary -- both in the list and outside -- which does admittedly obscure the part that is the answer, but that could be corrected with some editing.
In general, additional information is allowed as long as it's relevant and doesn't distract from the important parts. Answers that only duplicate another existing one have no value, but answers with extra background are helpful too, provided they can stand on their own. (If they're just an expansion on something someone else said, a comment would be appropriate.)
Also note that the question was on Hot Network Questions for a while; that tends to inflate voting far beyond normal levels.