Thanks to @HawkinsSecurity for bringing this photo to our attention. The officer behind the sign has a 33rd extended glock magazine in what looks to be a Glock 19 fitted with a Glock weapon light. I do not have any context as to why they are aiming so high nor why they are deployed. It may be the same officers that arrested the Paris massacre mastermind Salah Abdelsam by French and Belgian authorities.
They look similarly dressed as the officers in this video.