I know Kipax and myself disagree on this one..
I stay on the sidelines - on the left-side of the goal (I think) - so that I can shoot both the penalty taker and the keeper.
As you never know whether it'll be the kicker or the keeper that decides the shoot-out.
This way - if you are shooting for a club, you can alternate between shooting the keeper and the penalty taker.. without changing positions.
Fair enough, you might not get the players running directly towards you, but you'll get more of 'facing towards you' than in your example images.
But - as with so many aspects of sports photography.. there is no right or wrong - what suits one person, might not suit the other one.
From my penalty shooting experience - in three 'important' games I've covered, it was always a save by the keeper that decided the game. So then getting the keeper making the save and celebrating was what got used the following day as the 'number 1' picture.