Various items of art and public installations

By the way, the elderly people on the sides of buildings was a 2012 installation art project, read about it and see more pics at:

https://www.citylab.com/design/2012/07/old-people-appear-floating-over-montreal/2520/

How did the chairs stay put?  How did the old people get up there?  How were they secured and protected?  Beats me.