Another Twitter user replied to the screenshot: "The ignorance omg," along with a crying face emoji.
Someone else replied: "Why would she think this is a good idea? why do celebrities not use logic? why."
A Twitter user said: "I don't think the kids down the street who lost their mother to Covid would find this funny."
A fourth said celebrities aren't impacted by the virus: "They aren't affected by this at all. They still go out, travel, make money hang out. Then post stuff like this trying to seem like they relate w/ us and all it shows is that they don't."
However, a number of fans stuck up for the actress, saying it was a joke and people need a laugh.
"I think it's funny. Y'all can't take a sarcastic joke ..." one of them said.
Another added: "Sad part is she's probably right. The amount of pandemics has gone up in the 21st century considerably compared to the 20th mostly due to human activity and climate change. Even if I doubt there will be another one this global, local pandemics are guaranteed.
Another Twitter user said: "Wow!" and "It's just a freaking ornament people."
One pointed out that "sometimes you have to make light of bad situations instead of crying about them".
Aniston has previously posted about the severity of the pandemic earlier in the year.
In mid-July, Aniston posted a photo on Instagram of her and her Friends co-star Courteney Cox's friend Kevin, on a hospital bed with a ventilator.
Aniston wrote that he was "perfectly healthy" with no underlying health issues.
She added: "This is Covid. This is real.
"We can't be so naive to think we can outrun this ... if we want this to end, and we do, right?"
Aniston urged her followers to "PLEASE #wearadamnmask" and do it for their families and themselves.
"Just think about those who've already suffered through this horrible virus," she said, adding that Covid-19 affects people of all ages.