SOME Twitter users have been up in arms over this normal looking photo, but what is it that’s got them worked up? Can you spot the problem?

The Mirror reports that the photo isn’t some kind of optical illusion. But as some users noted, the man is allowing the woman to walk on the wrong side of the sidewalk — the side closest to the road.

“I’m sure half of you guys don’t even know what’s wrong with this picture. Smh (shake my head),” Twitter user ibi said on the original post.

Many were utterly clueless as to what the issue was, but many, such as Denzell Lowery saw it straight away.

“He should switch sides with her and hold her hand,” he commented.

“I think it’s just the ‘gentleman thing’ to do. just like opening doors. some women may not like that, but it doesn’t change,” another said.

I'm sure half of you guys don't even know what's wrong with this picture. Smh pic.twitter.com/RU1jUxWqAI — ibi. (@ibi_babyyy) May 19, 2015

According to Modern Gentleman Magazine, for men: “While walking down the street you should walk on the right side.

“No need to mention but if you have an umbrella with you, you should not swing with it. You never know who you might hit and hurt.”

“If you are walking down a street in the company of a woman or a man know that the right side is honorary side. You will let a woman walk on the right side of you or a man if he is a senior person. In this way we honour them,” the magazine state.

“This custom dates from the middle ages when knights wore the sword on the left side keeping the right side free, since the right arm was ‘fighting arm.’”

COMMENT: Is this a thing of the past? Or is it a rule that men should still follow?