The guy in that second pic is Kyle's Austrian brother, Arnold Katarn.
Actually the Kyle in the first picture bears a strong resemblance to the Kyle in Jedi Knight, so I don't think Raven should change his appearance too much, if at all.
Of course the Kyle Katarn we know from Dark Forces looks completely different from both Kyle and Arnold Katarn as shown in these two pictures.
Judging from the intermission cinematics in DK, I'd say Kyle bore a striking resemblance to a disgruntled Jeff K at the time (same hairstyle for example).
The really disturbing thing is however, that although he *looked* like Jeff K, I remember Kyle *screamed* like Zach de la Rocha (of Rage Against The Machine fame) when plummeting towards his death from an icy cliff as he was wont to do in those days.
I must confess, this strange discontinuity has really kept me puzzled for countless sleepless hours on end.
Dark Forces Forever!