Though it very obviously evokes Christ (looking depressed and wearing a crown of thorns), it's actually supposed to be Mindaugus in the attitude of Christ -- though I'm not certain what he's go glum about. Maybe it's because there would be no further kings, unless you count Mindaugus II ... which most Lithuanians don't (more on that in the video below). I'm guessing the crown is not supposed to be thorny in this case.
I've photographed him on top of a stack of 8x11 paper, for perspective.
Below is a video of a much larger statue, and a little about the position Mindaugus holds in the Lithuanian culture.