Usually when people ask me top or bottom ------------- 
But I went bottom and it should be a bow tie.
Good point about the shirt. The loop of the tie is supposed to be hidden under a collar. So the question becomes where should the collar be on a giraffe’s shirt? Answer that and you’ll know where the tie should be.
That’s Gr-r-reat!
This is what tie clips or tie tacks are for.
As for this, if humans really did develop four-foot necks, clothes would be tailored to accomodate (perhaps with a long neck section), or people would wear shirts as they do now, but leave the neck bare. (I’ll bet that the jewelry designers will have a field day designing elaborate necklaces, though.)
And again, if a human with a four-foot neck wears a tie at the bottom, it drapes over his chest. But that’s not the case for a giraffe, since he really doesn’t have a vertical chest. So it really might make sense to wear the tie at the top of the neck and drape it over the neck.
Yeah, stovepipe, for irony.
Tie at the bottom, otherwise it gets dunked in the waterhole* every time the giraffe tries to drink.
*or grabbed by a crocodile