This is under the entrance canopy of the Canadian Real Estate Association's national headquarters at 200 Catherine (to help locate it, you can see the nearby intersection of Bank and Catherine reflected in the building's mirror finish). The lot has plenty of landscaping at the fringes (like at Bank Street between Catherine and the 417), but the building itself is surrounded by parking and hard surfaces. This concrete planter box was installed at the entrance, perhaps to break up all the concrete, brick and glass.
But the flower planter seems to provide too much excitement, necessitating this hand-made sign shooing away people who might sit on it. The people who want to sit on the flower box are likely not doing so to spite the flowers, but because they want a place to sit. As the population ages, it's important to provide frequent seating opportunities around town to allow seniors to remain active but give them a place to rest (I know of many older adults who will walk to Hartman's and rest on the bench before going in to shop).
Considering that this is the only building on the block bounded by O'Connor, Catherine, Bank and the 417, my suspicion is that anybody who might want to sit there either works in the building or is visiting it (perhaps on a smoke break or waiting for a ride).
So why don't they just add a bench?
[Tune in on Wednesdays at noon for a new pedestrian-themed blog post. View the Pedestrians label for previous Peds on Weds posts]
[Look for more one-photo posts under the label Singles]