No idea. But this is Orchard Road after all.
Maybe many PO were on the scene but these have higher IQ and they know how terrible it looks to all the rich foreign tourists if someone is hand cuffed for taking photos or videos.
According to what I know, if a PO is at the scene and He does that, the first approach is to warn him to get off the road and not make a scene. If after some warning which is usually at least 3 times, he will be arrested under penal code # 268. Public nuisance
268. A person is guilty of a public nuisance, who does any act, or is guilty of an illegal omission, which causes any common injury, danger or annoyance to the public, or to the people in general who dwell or occupy property in the vicinity, or which must necessarily cause injury, obstruction, danger or annoyance to persons who may have occasion to use any public right.
Explanation.A common nuisance is not excused on the ground that it causes some convenience or advantage.
Obstructing public servant in discharge of his public functions
186. Whoever voluntarily obstructs any public servant in the discharge of his public functions, shall be punished with imprisonment for a term which may extend to 3 months, or with fine which may extend to $2,500, or with both.
Disobedience to an order duly promulgated by a public servant
188. Whoever, knowing that by an order promulgated by a public servant lawfully empowered to promulgate such order he is directed to abstain from a certain act, or to take certain order with certain property in his possession or under his management, disobeys such direction, shall, if such disobedience causes or tends to cause obstruction, annoyance or injury, or risk of obstruction, annoyance or injury, to any person lawfully employed, be punished with imprisonment for a term which may extend to one month, or with fine which may extend to $1,000, or with both; and if such disobedience causes or tends to cause danger to human life, health, or safety, or causes or tends to cause a riot or an affray, shall be punished with imprisonment for a term which may extend to 6 months, or with fine which may extend to $3,000, or with both.
[51/2007]
Explanation.It is not necessary that the offender should intend to produce harm, or contemplate his disobedience as likely to produce harm. It is sufficient that he knows of the order which he disobeys, and that his disobedience produces, or is likely to produce, harm.