When is bringing a baby to a concert not OK? Apparently, when that baby is lying on the floor.

At least that's the consensus of social media after a photo went viral this weekend showing an infant flat on its back on the floor of Taylor Swift's Eras Tour concert Friday night at La Défense Arena in Paris.

The controversial picture − allegedly snapped at the show by another attendee, @jacnights13, and then shared by a range of Swiftie fan accounts − depicts a baby wearing a light-up wristband in the pit area (no seats) with a person, presumably one of the parents, hovering over the child. The account has since been made private.

Related shots have surfaced online, including one posted on X by @irondaya, which showed the baby on the floor seemingly snoozing away while fans milled around. "The lack of common sense is astonishing to me," the post read in part.

While the baby did appear to have noise-reducing headphones on, the image of an infant lying on the ground − while adult feet stomp around dangerously close around it − generated largely alarmed reactions, says fanfluencer Olivia Levin, who shared the image on her popular Instagram account, Swifties for Eternity.

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"From what I’ve seen, mostly people were appalled by it," says Levin, 24, of Nashville, Tennessee, who says she decided to take her post down because the baby's face wasn't blurred out.

"Sure, a few people in my comments and DMs said to me, 'You’re not a mother or parent and can’t understand what we do for our kids, it's my only opportunity to see a Taylor Swift concert.' Others said that they parent different in Europe, which was interesting," she says. "But most completely disagreed. It brings up an important conversation about how young is too young to be at a show."

At the innumerable Taylor Swift concerts she has attended, Levin says she has seen young girls and even toddlers, but "never a baby."

Typical of the horrified reaction was a comment on X by @whatamind13 next to a photo of a thoroughly packed stadium: "just to paint the full picture this is general admission at the Paris show tonight… and that baby is somewhere in the floor AT THIS SHOW! ... terrible parenting."

The rules around kids at shows can vary from promoter to promoter, venue to venue and country to country. Generally speaking, the rules are actually guidelines. The only restrictions might revolve around the age at which a child must show up with a ticket as opposed to going in free.

The La Défense Arena website notes that the venue “doesn’t recommend bringing children under the age of 4, even if accompanied, particularly due to the high volume.” It also notes that strollers are prohibited, which would explain why this Swiftie could only rest their baby on the floor.

A venue spokesperson told the New York Post's Page Six that the fan in question would have been offered a place to sit: "For spectators with a young child in the floor, an alternative seating arrangement has been proposed but refused by ticket holders.”

A quick Google search reveals that plenty of parents are seeking guidance on the best way to bring a baby to a concert. Others ask whether the practice is wise.

A blog post on the e-commerce site Tushbaby asks "Can you take babies to concerts?" and advises that infants wear earplugs and, when possible, be taken to concerts that are "appropriate for their age and temperament." Beyond providing food and drinks, parents should be prepared to leave if the experience proves overwhelming for their baby, the post says.

The website Scary Mommy, which connects mothers on a range of parenting topics, featured a post a few years ago from a San Antonio woman whose sitter canceled at the last minute. That led Katarina Garcia and her partner to decide to buy some headphones at take their 5-month-old son to an all-day outdoor rock concert.

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Among the positives of her experience: Babies are often free at shows, music "is great for a child's development," and your "baby will be more adaptable."

"Taking an infant to a loud concert may seem anxiety-inducing, but it can also be a lot of fun and a great way to make memories," Garcia wrote. "I’m grateful I did it, because who knows if my son will ever get to experience Fleetwood Mac as an adult."

The American Academy of Audiology warns that children risk hearing loss if they are exposed to prolonged loud noises, with concerts ranking just below gunshots and jackhammers as hearing killers. Exposure beyond 30 minutes at a time is not recommended, according to their guidelines.

But what about just buying a pair of noise canceling headphones, is that enough to bring baby to the show? Not so fast, says Linda Dahl, an ear, nose and throat specialist with Northwell Lenox Hill Hospital in New York City.

"Those earmuffs can reduce noise by maybe 30 decibels, but concerts can be more than 100 decibels,” she says. “I’m not a fan” of earmuffs as a solution.

Dahl notes that babies have particularly sensitive and not-yet fully developed ears, and many of them often hear loud noises in an amplified way compared to adults. What’s more, any tests on babies to determine if there are hearing issues are inconclusive for the simple reason that babies cannot tell you if they are hearing something or not, she says.

If babies do have to be exposed to loud noises, beyond using ear muffs make keep the exposure to 20 minutes on and 20 minutes off, she says.

Getting a Taylor Swift fan to leave the show every 20 minutes is likely a tall order, doting parent or not.

Says Dahl, “At that, you might just think, 'Do I or my baby have to go to the concert?' ”