Tahno is talking to Korra before the final match of the pro-bending championship tournament. He might be trying to bribe her or something, whatever he's doing Korra does'nt fall for it.
I was planning to upload this picture before episode 6 aired, but I did'nt get it done in time. :/ Anyway, here it is.
Edit 11 june 2012: Thank you very much for 1000+
lineart for this picture: [link]
Korra & Mako: [link]
Korra & Tahno - Legend of Korra (c) Nickelodeon, Mike & Bryan
Art (c) BlueDecember89