There is nothing in Laserfiche that will automatically create an account for Snapshot and assign it licenses.
Like all Laserfiche applications, Snapshot needs to be able to connect to the Laserfiche repository. Since Snapshot will create a document in Laserfiche, a named user license is needed for that connection.
If you set up Snapshot as a local printer, then it can use the current user's credentials. So in this case, there is no need for the extra user.
If you set up Snapshot as a shared printer, then it needs a connection profile for logging into Laserfiche. It is possible that whoever set it up created that user and gave it a license.