Shooting Star's messages about Blaine

I can't help but feel like the writers were trying to send us several messages about Blaine in this episode. While there wasn't a particular focus on Blaine during the shooting, the camera cut to him an awful lot of times, recording the changes in his reaction which mirrored the change in his emotions. It was little moments that came together to form a big picture that not only addressed the common fanon theory that Blaine's parents aren't accepting, but also divulged subtly the impact Sadie Hawkins had on Blaine's psyche while staying true to who Blaine is as a person. 

• Blaine's initial reaction to the shots:

- While everyone was scrambling to the nearest corner, Blaine was moving the piano to create a place to hide then helping Artie sit on the floor. He was the one to question whether the sound they heard was a gun shot or not, and he was the first one to reach for his phone the second Mr. Shue told them to start telling people.
- This is consistent with how Blaine was portrayed from the very start. As a leader (Warbler's lead soloist, the New Rachel, Student Council President, etc) and a planner (planning to infiltrate the Cheerios to topple Sue), as someone who doesn't fly off the handle without proof (refusing to believe that the warblers cheated until he had concrete proof)

• Reconciling the panic of the situation with Blaine's 'collected' persona

- Blaine was trying so damn hard to keep a level head in an impossible situation and not to let his panic consume him. It was like he was rationalizing the situation so as not to get crippled by his panic and was forcing himself to be as calm as possible and think. But he broke when someone jiggled the door handle. He crumbled, pressing his palms to his eyes as if saying "this isn't happening". He was petrified and there was no masking it.

• Showing Blaine exhibiting what could be viewed as PTSD

- Blaine was the only one not touching someone during the shooting. All of the others were seen holding hands, hugging and leaning against each other except him. He put a little bit of distance between him and Artie and only touched Sam once until they were told they were safe. When Will was wrestling Sam into submission, he pressed his hands to his ears, trying to block what was going on. He was sitting with his knees pulled to his chest and at some point, he just curled into himself, making himself smaller.
- When everyone was telling Ryder to hang up, they were frantic and forceful while Blaine was positively terrified. He couldn't even talk so he mouthed "hang up the phone, please" at Ryder. After the shooting ended, he was sobbing into Sam's shoulder.

• Stressing the bond between him and Sam and between him and Tina

- He tried to hold onto Sam to prevent him from standing up (his first physical interaction with anyone since he helped Artie out of his chair, since he physically distanced himself from everyone else) and he clung to Sam after they were given the all clear.
- He acknowledged that Tina wasn't with them in the choir room (a fact that everyone already knew) and the scenes in the hallway and the auditorium.

• Subtly reminding the audience that Blaine is just a teenager

- After The Break Up, there was a lot of hate on Blaine which only got worse after the crush on Sam. Blaine looked utterly young throughout the shooting. It was bleeding through several things like the curled up position he adopted and the fact that we could actually hear his sobs when he latched onto Sam after the shooting. It only intensified when he was the only person showed to be calling his parents and his 'hey mommy' was audible.

• Telling the audience that Blaine's parents aren't homophobic or cold

- Despite the presence of some subtext indications of that before ( Blaine's parents agreeing to let him transfer because he wanted to be with his boyfriend and Kurt being present in Blaine's house twice with the door closed (Michael and The First Time) and we had confirmation that Blaine's mother was there in Michael), Glee made sure to tell us that Blaine's parents are in fact loving and caring, with Blaine being one of only two characters to mention the parents reaction.
The subtext development of Blaine's character and how Glee is giving him more depth is just wonderful. And Darren Criss deserves a round of applause for his perfect capturing of Blaine's emotions. In an episode filled to the brim with amazing performances (i.e, Chord Overstreet and Heather Morris), Darren managed to tug at our heart strings and deliver one of the most heartbreaking and most realistic performances.