The harp is a lie.

[MeowMeow]

Maybe all of you are looking at the bow wrong. Maybe it's not a harp at all. I've heard a few people say that the "harp" on the bow may be simply a quiver attached to the bow to hold a few arrows, and they may just be aesthetic... However, when i look at the bow I don't see those arrows (not a harp) being for looks at all. There is a REASON they're shorter than the normal arrow, and I will show you why I think that is, below.

Crappy MS Paint Depiction

Now, they have already confirmed the bow does in fact transform, but I'm thinking we all have been coming up with the wrong ideas of how that happens. What I think this "harp" which happens to clearly have fletchings and arrow heads on the "strings" flips down, into a platform that holds 4 additional, smaller arrows. Then when the string is released, it hits some sort of firing mechanism in the center of the arm that folds down, and launches these additional arrows. In other words, i think archer is going to be getting more AOE potential once the jobs hit. I don't think each of these arrows will hit the same target, but any target in a cone before them when using basic attacks like Light Shot and Heavy Shot.

My opinion on the matter is that the "transformation" will be entering AoE mode, or Single target firing mode.