Spike fluffing his pillow.
"That would be... awesome!"
Spike surprised- Twilight doesn't have confidence in herself?!
Spike can't sleep... the reason why is off-screen.
Spike holding the fake Element of Magic.
Spike, thinking: "I can't let Twilight go through this alone! She's like my big sister!"
Hang on, Twilight- Spike's a-coming!
Spike doesn't like getting stretched!
I'm a... dog? What the...
Jeez, Twilight- I know this is a lot to take in at once, but come on!
"Like you... only not you. Your muzzle's really small".
"Are you gonna scream again?"
"Look on the bright side- you don't have those pesky wings to worry about any more".
Twilight- "You're not helping, Spike". Spike- "Sorry".
"I don't think this is a castle".
Spike's just as scared of this new reality as Twilight is.