That face just says “Somepony is about to get a beating.”
 
@TarivGy  
As to what scene that’s from, it is when they meet Capper and he’s charming Rarity.

@Flutter_Lover  
When they were falling after Spike stopped being Godzilla? Spike was talking, Rarity shushed him, tears in her eyes, then they get stopped from splattering on the ground by pegasi with a banner. You pretty much described that scene but in a different setting.

@Background Pony #E4A0  
Uhh….no they didn’t.

Remember he has a body count in this movie.

@Flutter_Lover  
They did that already, though.

Know what the movie should’ve had?
 
A scene where the Mane Six are were falling down to Mount Aris, Rarity screaming while Spike floats down near her and says, “Rarity, before we fall to our impwnding doom, there’s something I’ve been really quiet about it since our journey, and this is the time I want to get it out of my chest!” Rarity replied with a quick gasp, “Oh, Spike….”, she then sniffles with her eyes drenched with tears as she felt her heart has been touched by his soon to be delivered choice of words. “Go on…don’t hesitate. Say what your heart feels!” Spike and Rarity’s eyes locked on each other’s faces, leaving Spike a little hesitant but reluctantly became confident. “R-Rarity…..” Rarity’s eyes gleam with a reflection of Spike holding her hooves. “I lo….WHOOA!!” Spike yelped as Twilight magically grabs her friends to the basket of the hot air balloon.

I are serious Spike.

this scene shows us that spike will continue to fight for the love of rarity although in the end it does not matter, rarity will not end with spike, everything will be in vain

I don’t remember very angry Spike. What scene is this from?