What is the difference between "is_connected" and "is_online" status?

I was wondering how to interpret this output. In the example below, the first output shows staus "is_connected"=Trye and "is_online" not, but in the second, both are True. What has changed?

$ dbus-send --session --print-reply --dest=com.ubuntuone.SyncDaemon --type=method_call /status com.ubuntuone.SyncDaemon.Status.current_statusmethod return sender=:1.141 -> dest=:1.149 reply_serial=2
   array [
      dict entry(
         string "is_error"
         string ""
      )
      dict entry(
         string "is_connected"
         string "True"
      )
      dict entry(
         string "name"
         string "SCANNING_WITH_BOTHQ"
      )
      dict entry(
         string "is_online"
         string ""
      )
      dict entry(
         string "description"
         string "doing server rescan, BOTHQ waiting"
      )
   ]

Later:

$ dbus-send --session --print-reply --dest=com.ubuntuone.SyncDaemon --type=method_call /status com.ubuntuone.SyncDaemon.Status.current_statusmethod return sender=:1.141 -> dest=:1.155 reply_serial=2
   array [
      dict entry(
         string "is_error"
         string ""
      )
      dict entry(
         string "is_connected"
         string "True"
      )
      dict entry(
         string "name"
         string "START_WORKING_ON_BOTH"
      )
      dict entry(
         string "is_online"
         string "True"
      )
      dict entry(
         string "description"
         string "start working on both content and metadata"
      )
   ]