@Jarkes  
well, in the animatic she look scares.  
in the episode. she have more of a “i dont know what is going on” expression

@sargesprinkles  

@Jarkes  
http://derpiboo.ru/480230 this does look like fear

@Mayojar77  
i see word of god thing, but so far that hasn’t been brought in the show

@Mayojar77
 
Yeah, even before that whole thing in the comics happened, there were a few mentions of something along those lines. In fact, note how, in the episode, Luna has a brief look of fear on her face before she fully transforms.

So to recap, it’s…  
Celly = Magic, Kindness, Generosity  
Luna = Loyalty, Honesty, Laughter

@Background Pony #CF55  
Oh right, I was thinking about what Celestia had for a second.

Maybe they weren’t so picky back then.

@sargesprinkles  
Word of God has implied many times that she wasn’t completely herself at the time and that something else was going on.

@Prof.NightJack  
Kindness is pink, Luna has Laughter.

maybe just because she is grabbing it it doesnt mean she is the incarnation of such element.
 
or her traumas pushed her to hard, so she just became unworthy later.

I notice Luna also has the element laughter.  
Yet she has to ask Twilight “what is this… fun… you speak of?” in Luna Eclipsed.

@Mayojar77  
really?  
when?

It’s kinda implied Luna wasn’t entirely under her own control.

And look at the other two, honesty ans kindness, ouch.

It’s a bit of a sad irony, if you think about it.

Guess thats part of why the elements then all belonged to Celestia for the time being.