"It is in really bad taste," Wills said.
"There is a line you cross from a joke into bad taste and taking advantage of children. This crosses that line."
The Herald on Sunday was alerted to the photo this week and sent it to Wills. He said anyone who supplied alcohol or cigarettes to a minor was breaking the law and open to police prosecution.
"It is a really stupid thing to do. It is not funny. Supplying alcohol and cigarettes to a child is never in their best interest."
Michael Colhoun from Action on Smoking and Health said the photo was worrying at a time the Government was considering plain packaging to make cigarette smoking less attractive to consumers, especially children.
"This renormalises smoking and the message that it gives this young kid is not a good one. We are working hard to make smoking less normal and the message they are giving this young kid is this is a normal thing to do."
It is not certain if the cigarette was lit or if smoke in the photo was digitally altered, but Colhoun said either way it was not acceptable to put a cigarette in a child's mouth.
Alcohol Healthwatch director Rebecca Williams said exposure to alcohol at a young age was also extremely harmful.
She believed encouraging a child to drink and smoke, or even to pretend, was abuse.
"People say there is personal choice but this kid didn't actually have a choice. He was put in a position of drinking or pretending to drink at an early age where his brain is not developed enough to make a choice.
"They are preparing and grooming that child for future use. If people do think it is acceptable then it shows how far we have to go to."
Comments on Sharie Cooper's Facebook page describe the photo as "cute", "classic" and "cool".
The older brother has also posted the photo on his Facebook page and jokes: "Had to bum a ciggy an a brew of the lil bro for the photo hahaha."
The Coopers did not respond to an interview request.