Looks like talking normally in a convo is not enough for this character. Just starts rambling on and on, even naming the enemy.
Interestingly enough, the portrait gets layered behind various GUI and the mini-portrait loads whatever it feels like, and its text gets changed to the convo. Text progresses like normal, continuing scrolling whenever I input a button, but disappears when I go to the R menu screen. A one time glitch though, but interesting nevertheless.
Also, comment number 666 is mine!