This is a caravan going around Madrid by the Ahora Madrid city government for citizens to put their votes into how they would like money spent on development of public spaces (squares, parks, etc). The online voting system is an extension of a platform developed just after 15M, in which the proposals that people wrote down on pieces of paper in Puerta del Sol were then input into the digital platform so that people could place their votes for their favorites. The ones with the most votes were the ones pushed forward...

https://www.facebook.com/AhoraMadrid15/videos/vb.1589610151285730/1767719600141450/?type=2&theater