Peer into the window at 89 Brighton Ave. on Tuesday night, and you’ll see the warm, flickering light of roughly a dozen tea light candles and the silhouettes of the warrior pose, child’s pose, downward dog — this is candlelight yoga.

Held in a large room flanked by old-school arcade games and taxidermied animals, and warmed by space heaters and stretching bodies, candlelight yoga marks the return to Allston of yoga that exists on donations. Free mat rental is available, and the suggested $10 donation is just that — a suggestion.

Brought to Allston yogis by Yoga Hub Boston, candlelight yoga is one of three classes designed and taught by Ali Singer at the community pop-up space known as POP Allston, which opened in September. It’s the handiwork of a consortium of community groups and businesses, in conjunction with the City of Boston.

POP Allston bills itself as “a free place for small businesses to grow, kids to skateboard, people to fix their bikes, and artists to create.’’ An indoor skate park, a vintage market, and a do-it-yourself bike shop (among other things) call it home.

“You wouldn’t find taxidermy in many yoga studios,’’ Singer said.

Singer said she tweeted at Mayor Martin J. Walsh when she saw the POP space was opening, asking if it could be used for yoga. To her surprise, the mayor responded.

Singer then began preparing to teach classes, tailoring them according to the time of day, the space, and the demographic. Of the ideas Singer pitched, reggae, glow, and candlelight yoga were the ones that stuck.

“Reggae vibes go along with yoga vibes,’’ Singer said. “They’re all about unity, and it seamlessly aligns in that way.’’

Glow yoga is performed with a black light and neon, and is popular on the West Coast, Singer said.

“I love electronic dance music, and it’s a high energy class,’’ Singer said.

As for the candlelight class?

“The candle is symbolic of universal energy, like the fact that we are all one, that we all come from the same stuff,’’ Singer said. “So the idea is to all light our candle from the same, single candle.’’

Boston University sophomore Nikki Reyes, 19, said she likes the creativity that animates the classes.

“Instead of just normal vinyasa flow, she does candlelight, the reggae one, and then the glow yoga,’’ said Reyes, who helps Singer with marketing, before adding that her favorite is glow yoga.

“It’s more upbeat.’’

Singer, who has been teaching yoga since 2013, taught at Allston’s previous by-donation yoga space, Karma Yoga Studio. Karma closed in 2014.

According to Singer, Karma “definitely inspired this donation-based yoga class format.’’

“I just love the idea behind donation-based yoga,’’ Singer said. “A lot of studios are really expensive, and it’s pretty hard to develop a regular practice when the studio fees can just put you out. I wanted to make yoga that was pretty accessible to everyone.’’

Since September, Singer said, she’s seen a whole range of people walk in for class — including one child.

“She comes with her mom,’’ Singer said. “She’s like 8, I think.’’

Loris Matar, a 29-year-old who lives in Allston, said Tuesday’s candlelight class was her first at POP Allston.

Matar, who said she took the class in part because she “needed to find [her]self on the inside,’’ said she also plans on attending the glow and reggae classes.

“It really does feel like it’s a part of the community,’’ Matar said in Spanish.

Aimee Ortiz can be reached at aimee.ortiz@globe.com. Follow her on twitter @aimee_ortiz.