Your set up instructions say
Important! Do not use a line filter/splitter (from your old ADSL service) when plugging in the Network Connection Device..
What do you have to do when splitter is wired into 2 phone jacks one for internet and 1 for phone?
See photo enclosed
Welcome to the community!
The instruction is correct for NBN service you are no longer required to use a Filter/Splitter for NBN-FTTN,FTTC, or TPG-FTTB.
All these information are available on this article below.
In your case, the wall socket you posted is the old type 610 socket which requires a 610-Adapter for the modem/router to connect.
On the other hand, if you have received the modem/router for your NBN service we recommend not to set it up for now and use the current ADSL2+ modem/router as the installation is still in progress, an NBN technician is scheduled to visit the premises to complete the installation.