@Itsthinking  
I suppose she could open up to the idea if she lived among ponies long enough. However, for the time being Jade isn’t even remotely interested in ponies that way. Interspecies relationships aren’t everybody’s thing, and that certainly goes for Jade.

@QueenCold  
Good to know.
 
Could you see her seeing a pony in that way, or would she prefer a dragon?

@Itsthinking  
She will

@QueenCold  
Awwww….
 
She’ll find a noble dragon (or stallion) to love her someday.

@Itsthinking  
Jade is very afraid of losing her friendship with Spike or making it awkward, not because it’s a stepping stone to becoming his girlfriend in her eyes, but because it’s a good friendship and she likes it as it is. She sees how crazy Spike is about Rarity and to cope with the unofficial rejection, she tends to downplay her own feelings. The more she learns about Rarity, the more she sees herself as unworthy and her own crush as superficial, all because she glorifies Spike in her own mind.  
When she learns that Rarity uses gems to adorn garments with, she dismisses that notion as silly. But when Rarity explains she does it to bring out the inner beauty of other ponies, Jade concludes that Spike loves Rarity for very deep reasons and that is why she doesn’t stand a chance.  
Though she would love to be Spike’s girlfriend, she can only see herself failing and losing what she has.

@QueenCold  
Ouch.
 
Not being forward is only going to lead to situations like that.

Dammit Spike! Pay attention to the adorable dragon girl!

@Itsthinking  
What’s got her upset the most is what happened prior to this scene. At this point Spike already knows Jade knows about his crush, but he is still utterly oblivious to Jade’s crush on him.  
So what happened earlier was:
 
Spike: “Jade, would you go to the dance with me…”  
Jade: :D  
Spike: “… if you were Rarity?”  
Jade: :C … :) “I don’t know, have you asked her?”  
Spike: “Not yet, I’m afraid she’ll say no.”  
Jade: “Well, if you don’t ask her, how are you gonna get a ‘yes’?”  
Spike: “I guess you’re right. Thanks, Jade, you’re the best!”

@QueenCold  
Her face does look like >tfw friendzoned.

@Itsthinking  
She doesn’t mind trying on the outfits Rarity makes for her as much as she says she does. Rarity makes her this particular dress, because her other gala dress got ruined and she’s secretly ecstatic with it.  
She’s sad because Spike is fawning over Rarity right in front of her.

She just looks so sad…
 
Sick of being a living mannequin for Rarity’s fashion?