If this mare really is a version of you—and deep down, you can feel that she is—then there's a chance that despite whatever molded her into this twisted mockery, she might still share some of your most fundamental fears.
Fears that you've been getting very well acquainted with today.
With that in mind, you take the stack of Paperwork out of your Inventory. Jackpot! An almost invisible wince at the sight of it. Now you just need to roll with it.
"Alright, I accept. But if I'm going to be involved in any experimentation then you're going to need to sign a few things."
Her flinch is visible now. "S-sign? No, I don't think—"
"First there's the standard release forms." You lay two sheets atop a nearby machine. "Followed by ones for physical, mental, and spiritual safety." You add more papers to the pile.
"You can't—" she tries to interrupt but you steamroll over her objections.
"If you're going to be using any previously undocumented techniques then you'll need to file forms with the Bureau of Health and Pony Safety, the Department of Science, and the Medical Board. They should get back to you in a few weeks." You step forward and place the new papers on a different machine.
Your double's eyes practically pop out of her head. "Weeks?! We're doing this now!"
You suck air through your teeth. It's amazing how easy it is to slip back into those memories of office life. You never had to deliver this kind of news but you remember many managers who did. Parroting them is as easy and natural as mimicking your friends. "Mmm, yeah... That's not gonna happen. If you want you can file a priority request with the Minister of Efficiency—" another paper on another machine as you start to circle around her to find more space "—but he's on vacation so you really should have filed it last week."
"Last week I didn't—"
Her proud stance is gone, now cowering in on herself as her eyes dart from one pile of papers to the next. Time to really lay it on.
"And while we're at it, when was the last time you had this place inspected? Gonna have to get somepony in for that. Take this service request form. Take three; they like it in triplicate. What about that trotsla coil? That have a permit? That's three forms for local, state, and federal permission. Oh, and another three for registration of it after the permit arrives." You heap papers into her hooves, intentionally letting them slip away from her so she has to scramble to collect them all up.
"Is that an open tub full of mysterious fluids? POSHA's gonna have your flank for that. Better get started on the incident reports now. And look at all these loose wires and pipes! That's an incident report for each one. Is this licensed? Is that cleared? Do you have the certification to operate these? Are—"
"Gah!" Other Rainbow Dash throws the papers into the air and clutches her mane, her body shaking like a frightened animal. "I can't take it! The paperwork! The tedium! The pointless bureaucracy holding back my work at every turn! This is why I left the Factory! Why I struck out on my own! To escape from all this bureaucratic red tape and actually make progress. I won't be sucked back into that world! You can't make me!"
She takes a running leap towards the sludge filled tub. "Better not alive, than nine-to-five!" she screams, laughing madly as she cannonballs into the tub and sinks beneath the surface.
A single bubble rises to the top and pops, but no more.
A ringing chime sounds throughout the room as you finally relax. Coming up with all the nonsense on the spot was not easy. It's a good thing she finally cracked because you were about to run out of plausible sounding things to need paperwork for.
One of the machines beside you rattles then dings before a sliding hatch opens towards you. Inside are two things. The first is a slim glass vial capped with a cork and filled with a rainbow liquid. Even as you give it a shake the colors don't mix and quickly separate back into layers. A small label on it reads 'Warning! Experimental Formula'. The second item is a small card with gilded edges with the inscription:
The inspiration for this room was drawn from the winning entry to the Ponyville Young Horror Writer's Club Nightmare Night short story contest. To read the story in full, come visit us Tuesday and Thursday evenings in the schoolhouse annex from six to eight. Ask for a copy of 'The Rainbow Fracturing' by Scooting Along and Aura Dog.
You have no idea who one of those ponies are, but the pen name of the other is so obvious you kinda wonder why she even bothered. Sometime soon you need to have a long chat with that filly about illegal use of other ponies' image in media.
You tuck both the note and the vial of Experimental Formula into your Inventory.
It's a shame about your counterpart, but there was nothing you could do to help and, in the end, she chose to go out on her terms. You can't fault her for that.
You leave the bathroom-turned-science-lab with a clear conscience, ready to continue your adventure. Though hopefully against less personally targeted frights.
There are six paths open to you from this point. There's a DOOR next to you and also two across the hall. The hallway itself continues both to the LEFT and RIGHT and also has a secondary path splitting off to your LEFT.