Yes, you certainly could stand in front of a broken or whole mirror, but we still haven't addressed why we use the verb for standing there to connote the action of waking there... If this is simply a Hungarian idiom that is routinely used, and the roots are lost in history, I will accept it as an idiom and move on. Otherwise, it doesn't make sense.
The use of walk seems wrong and there's no way of knowing. Equally, the use of up seems wrong. I have the same problem as the others in that I couldn't get past the fact of standing which, of itself, indicates someone who is stationary. However, the preverb "oda" insists there must be movement if I understand correctly. The next question is how you get to the standing position in English. Elfi 311 has given a translation which she favours and I can't think of a better one. The problem with it is that the verb, (i.e standing), is a future event and this is supposed to be the present tense. It's a messy question which conflates the movement of oda with the stationary nature of standing and English is too logical for that.