Aubrey Plaza is a pretty fascinating comic performer. I've seen her in less stage-managed interviews and snippets of work in which she's incredibly acerbic, smart and scathing, unafraid of treading on toes and social conventions alike.

Whenever she's in a movie, there's the inevitable danger that edge will be shaved off or reigned in. She was one of the scene stealing elements of Dirty Grandpa (and how many other young female actors can say they pretend-banged Robert De Niro?) and had a great role in Safety Not Guaranteed where she balanced vulnerability and smarts.

But even though casting her in the role of social media stalker Ingrid was smart on the part of director Matt Spicer, she wasn't used to full effect. Maybe the problem is that she was playing kind of an introvert, where Plaza herself seems to have a very strong force of personality.

But the movie does manage to juggle several tones pretty cleverly – it's not often we see a scene that effortlessly pillories the look-at-me veneer of the creative digerati generation and a suicide attempt in the same movie.

It also keeps you on your toes about how you're supposed to feel about everything going on. Are Ingrid and her apparent mental health issues the true antagonist, or is the world she operates in of social media obsession and projecting an aspirational fake life for the sake of fame dysfunctional, Ingrid just a victim of it?

Like Arthur Fleck in Joker, it's a bit of both, and the script does a good job of balancing the two and keeping you from ever being sure which is more damaging/damaged. The first inkling you get of that is the very first scene, when Ingrid when she crashes a wedding, enraged that she wasn't invited and spraying the bride with pepper spray.

But then later on there's a hilarious scene that by contrast makes her completely relatable (and it's one of the strongest ideas in the movie for me, as it happens). After swanning around living the life inspired by her favourite social media star, Ingrid sits down to eat some gluten free fair trade organic crap in a trendy eatery and immediately spits it out in disgust, whereupon we cut to her sitting in slobby clothes in her apartment cramming French fries into her mouth.

Ingrid lives and dies by her fandom of Instagram figures, particularly LA photographer Taylor Sloane (Elizabeth Olsen, and it's nice to see her do something outside CGI fights for Marvel again – after her debut in Martha Marcy May Marlene she leaped straight into the tentpole meat grinder).

With an unexpected inheritance and no impulse control, Ingrid goes to LA and sets about ingratiating herself into the perfect life Taylor projects online – shopping at the same boutiques, eating at the same artisanal cafes and reading the same books.

But she wants to get closer than just aping Taylor's life, and she crosses an unexpected line when she breaks in to her and her husband Ezra's (Wyatt Russell) house, kidnaps their dog and sits back to reply to their lost dog flyer pretending she's found him.

It's Ingrid's way in, starting with them insisting she join them for dinner because of her good deed, her and Taylor thereafter becoming fast friends. All Ingrid's dreams are coming true, and she'll sacrifice anything – including the honest and heartfelt interest by her landlord Dan (O'Shea Jackson Jr) – to keep the fiction up.

Where she expects it to end as she goes to increasingly desperate measures to keep it going (with human kidnapping and considering murder among them) Ingrid doesn't even appear to be thinking about, she's just like a drug addict maintaining her high of the social media-sanctioned dream life.

And when the wheels do finally fall off, she becomes like a cornered animal – irrational, desperate and fighting to her last breath.

There are a lot of peripheral themes around being true to yourself, the front we put on and how easy online life makes that possible, etc. You're never sure of the thesis Spicer and co-writer David Smith are outlining, even down to the final sequence when it's apparent Ingrid hasn't really grown or changed.

However much it's suddenly for a more authentic reason, she's still obsessed with likes and fans, and we leave her still ignoring Dan (who she doesn't realise is the only true friend she's had during the whole ordeal), her rapt faced bathed in the glow of her phone.

It might have been Spicer and Smith's way of leaving it all open ended or purposely not having a point of view in the whole mess, but I found it a bit less than satisfying. That probably goes to show I was invested in Ingrid as a character – I wanted her to come to her senses and get better, so maybe it was actually a neat trick to pull.

At the very least it's a role for a smart, funny woman, and there are never enough of them.