The photo was taken at an event Karam had held in celebration of the release of her latest album, 'Menni Elak.'
The cross is a coveted symbol of Christianity and is often worn by believers of the faith.
As the photo began to make the rounds online, many spotted the difference between the original and the photoshopped image.
Soon after, thousands began to share angry reactions over the magazine's post on social media platforms.
Here's how it all went down:
Sayidaty published this photoshopped photo of Karam
In the original, she's wearing a cross
People expressed their anger
"It's unacceptable for a respected magazine to disrespect anyone's cross."
Many were shocked
Muslims also objected the publication's decision
"Our religion teaches us to respect all other religions."
"Would anyone accept it if a publication photoshopped a woman's hijab out of a photo?"
"Why? The cross was and will always be a symbol of a religion practiced by our dear Christians. There was no reason to photoshop it out of Najwa Karam's photo."
"Enough of this regression... we're all one."
Sayidaty issued an apology
After the intense backlash the publication received on social media, its officials issued a public apology via Twitter on Thursday.
"Sayidaty published images of Najwa Karam that were edited by one of our employees who individually made the decision to photoshop them. We apologize for the unintentional mistake and stress on the fact that our publication respects all religions and co-existence. We thank everyone who pointed out the mistake to us."