I don't think you can tell anything from the photo. As a rough guide, you can slip a credit card under the strings. the strings should just touch the card at the 0 fret. If significantly higher than yes, the action at the nut is too high.
I have always thought that when pressing on the 3rd fret, there should still be some clearance in the 1st. Not a lot, but some. Others may want to comment as well...
You can only tell that the nut looks wonky. A credit card without indentions doesnt quite touch the strings at the nut (no zero fret), but will be held in place between strings and first fret.
Yes the photo isn't telling us much.
Do the strings feel too high above the frets?
Not sure how high they should feel, but I suspect it might be the case. About 1 mm at the first fret.
I suggest you see a doctor if it is painful, or if it is enlarged. Good luck!
The squirrel who lives nearby has a third kind of nut problem. He keeps telling himself that he can stop any time, but he cant...
I’ve set up maybe two dozen Ukes and the the whole lot looks wrong to me. The slots are too big and I would like to measure the strings to just check that they are installed in the correct order. The nut doesn’t appear to be level, it might still function but it’s meant to be level and it might not be properly seated in its slot.
I set my string heights by measuring them above the first fret, I aim to be just over 0.5 mm above the first fret. Other people might use the string depressed method. Yes, in that method, the the second fret should prevent the string from reaching the first fret.
I can’t recommend that a totally unskilled person tackles this work on a Cort (they are a bit too pricey for that). Either have someone who does know what to do sort this out for you - which could be expensive - or buy a cheap second hand instrument to learn on (an old painted Mahalo U30 can often be had for very little and is a great Uke to learn such skills on, typically they still have their original clear nylon strings on them and have never been set-up.). You might well still need further skills before starting on the Cort, but every journey has to start somewhere. The Cort has some similarities to my Ohana, I couldn’t have tacked that without learning on other stuff first.
Good luck.
The nut is indeed not level, that is why I posted the photo. The slots in the high end are deeper though, so it can still function. There is no gap between the nut and the neck.
I believe I stringed in the correct order, but I am about to change the strings anyway. They are starting to have what looks like shavings come off by the frets.
If 0.5 mm above the first fret is the way to go, taking 0.2-0.3 mm off might ease the playability. I think it is 0.9 mm now, hard to see with a ruler.
So to the dilemma - spend as much as the instrument cost to see a luthier, buy some expensive nutfiles and risk ruining the instrument, let is be as it is, or something third.
I doubt I am going to modify enough nuts for it to make sense to buy practice parts.
