The actress - who plays Tina Cohen-Chang in the Fox series - explained the film, which features the stars of the programme performing a live gig to 20,000 people during their 'Glee Live! In Concert! Summer 2011' tour, gave them "instant gratification".
When asked how she found the experience different to filming on set, she replied: "It's instant gratification. We get the energy and we feed off of that. Gratefully our crew is dancing along with us with every number that we do and they're amazing. But other than that, it's a small group of about 20 of us so it's just a totally different vibe."
Darren Criss - who stars as Blaine Anderson in the TV show - felt liberated by the experience of playing in front of a live audience and admitted the cast's fans were more "forgiving" than the TV bosses are when they record the TV show.
He added: "To experience all these people in real time is a pretty cathartic moment. There's this huge fan presence that is undeniable.
"It's very different than a set. Crowds are more forgiving than your script supervisor."