I can't reliably make out what the differences are myself. Appears the recyclable kind has a rice-like texture appearance to it and the non-recylable has a fine texture and is whiter.
make sure you use the correct bags. And check, one is usually for trash and an other for green garbage. Ours look the same, only the labelling is different.
people who feel lazy just store their trash and recyclabes on the balcony but reallly nothing stops you from bringing the sacks immediately to the container.
Nothing except the possibility of a fine if you are caught. Not to mention that neighbors probably don't appreciate it, either. I know that it pisses me off when pick up is Tuesday and there are already bags out on Sunday.
In Zurich it is perfectly o.k. to put the bag in the container an y time. Also bags must be in the container or wheely bin. That's the very purpose of those items and thus any building without a nearby underground container has at least one of those.
My upstairs neighbours do this, and in the summertime I get maggots raining down onto my balcony through the cracks. I'll be installing strips of duct-tape this spring to hopefully prevent that from happening this year.