I just gave my sister my MHL a couple weeks before getting this phone coming from the Nexus 4. Nexus 4 takes the Slimport. The port looks exactly as a regular Micro USB port, but this one on the G2 looks to take the MHL. If someone can confirm before I get the MHL back.
I can verify that Slimport does indeed work on the G2. Just got the cable and the connection is instantaneous. You can play your videos, watch pictures or mirror your phone any way you like.
Was it the right type of mhl? I bought a mhl adapter for my gs4 once and it didn't work or charge either because it was a different type of pins. I think there's 6 or 10 pin mhl. There's also MHL2 standard that's backwards compatible for 10 pin mhl1 phones