I recently found /snap/gnome-3-26-1604/ on my Ubuntu 18.04.1 machine. I found this other related question, but not much else to explain what it is used for. I also seem to have several versions of it: /snap/gnome-3-26-1604/70, /snap/gnome-3-26-1604/74 and /snap/gnome-3-26-1604/current.
What does this snap do? And can it be removed without breaking anything significant?
It should be this snap: https://snapcraft.io/gnome-3-26-1604
This snap includes a GNOME 3.26 stack (the base libraries and desktop integration components) and shares it through the content interface.
So, unless you have another gnome stack in usage, you should not remove it.
Edit: As snap always downloads a whole new version instead of updating and does not auto-delete the old ones, yes, you can delete the old ones. Check which are disabled with snap list --all and remove with snap remove --revision XXX gnome-3-26-1604 where XXX is the revision number (eg 70).
