They’re rubbish bins (or perhaps textile recycling bins, but probably not) specifically for national, regional, and/or local flags.
Edited to clarify: No judgment, I am not making a political or societal argument, just posting about a thing I learned exists. If this post gets hijacked I’ll ask the mods to lock it.
Are people supposed to thank the flag for its service before binning it?
I believe that’s part of the grief protocol, yes.