Red envelopes are a fun way to share your tokens with a bunch of people at once. You create them and load them with a certain number of tokens, then these tokens will be split by the number of users you choose.
You will be provided with a command for the messengers for people to open the envelopes and also a link you can share in other places like Twitter.
It's on a first come first serve basis so the first people to try to open the envelopes will get them up to the number you create. See below for an example.
To create a red envelope:
/redenvelope create 100 GO to 10 users
The above command will create 10 envelopes (for 10 users) each containing 10 GO tokens.
Once your red envelope is created, it will give you instructions on how to share it.