That looks like a combination of a lot of break material and general trub crud.
Generally speaking it's not a problem, though you do seem to have a ridiculous amount of it for such a small brew.
We might be able to offer a bit more specific guidance if you can write up your process in a bit of detail. I suspect though that you've gone straight from the pot you boiled in to the demijohn. If that is the case, you'll basically have any (perfectly normal) crap floating around in the pot going into the beer. You'll also then be cooling the wort in the demijohn which means cold break material may well appear (that's what it looks most like).
So if I'm right about that, the my suggestion would be to cool in the pot you boil in (I used to put the pot in the bath full of cold water til it reached pitch temp), hops and all, then pour it into your fv/Demi through a sieve. The hops will then act as a filter and catch most of the stuff you now have floating about.
I'd leave it, it will settle out and pack down, but what you might find is that it's tricky to bottle without disturbing it.
When you do bottle, move it to wherever it will be for bottling about a day before. That way if you slosh it about when moving it, it will have time to settle backdown. Then you just need to super careful when bottling.
The beer will probably be ok
But like I said, let us know your process and we may be able to offer more specific advice.
