Odd sound coming from rear derailleur

I have recently been doing minor maintenance on my road bike getting it ready for the nicer weather.

Most recently I have taken the chain off and cleaned the derailleur cage.

When I put it back together and replaced the chain I noticed this odd rubbing sound coming from somewhere on the derailleur, and I am not sure what it could be. It doesn’t sound like it is metal but what else could it be?

Is this something I should be worried about?

You can only hear it when it is moved very slowly both forwards and backwards.

I am pretty sure the chain is routed correctly, and it shifts properly through all 10 gears.

Thank you.

[Bonus Pic](https://imgur.com/a/OclkRsv)