Welcome aboard to the forum
From what I can see, it looks your Nokia box will automatically show what is coming in on its VCR/Aux SCART when something is detected. This likely happens in order to allow the DVD recorder to chain with the Nokia to allow both to connect together and only occupy one SCART socket on the TV. For example in this scenario, when one goes to watch a DVD, the Nokia would go into a ‘pass-thru’ state where anything going in its VCR/Aux socket is passed out the TV-Output such that the DVD picture is shown. Unfortunately, as you have an RF cable to view the Freeview from your Nokia in another room, unfortunately what ever is passed through is also modulated over its RF, thus explaining why you see your DVD recorder picture on your portable TV.
One thing that would be worth trying is press the ‘TV/Video’ button on your DVD recorder remote. As this toggles the voltage on ‘Pin-8’, there is a good chance that your Nokia box will only remain on ‘Pass-thru’ while this voltage is detected. Also, if your Nokia box has an ‘Aux’ or ‘AV’ button on its remote, try pressing this to see if this switches back to the Freeview picture.
If the above does not help, there are two other suggestions that would be worth trying, however this involves purchasing AV cables if you don’t have these already:
Method 1: Connect the TV-Out of your Freeview box to a 2xSCART Splitter. Connect one output to the AV input of your DVD Recover and the other output to your TV. As nothing is connected to the Auxiliary socket of your Nokia, it should not go into a pass-thru mode.
Method 2: Get a SCART to 2xAudio+Video Phono cable and a SCART->2xAudio+Video adaptor (SCART->Phono output or version with an in/out switch). Connect the adaptor to the AUX on your DVD recorder and the SCART->Phono cables on your Nokia. Set the switch on your adaptor to input (if present) and the switch on the SCART->phono cable to output (if present). This will prevent any signal from going from the DVD recorder to the Nokia box, however as it is not possible to send an RGB signal to the DVD recorder from the Nokia box with phono cables, the DVD recorder can only record a composite signal in this method, which is inferior to the RGB mode which can only be passed over a direct SCART->SCART from what I’m aware of.
Good luck with your setup