Hi Helge
I feel you missunderstood the question - but you are in good company with this, there are many users who do not really get it ;-)
The question is actually which end of the steps/stairs is higher up. As far as I remember StreetComplete shows you a direction and you can choose if it is up or down.
What I can see from the data the stairs are drawn in the direction towards Hamnleden and from your picture it seems that that end is higher up.
Correct? Then it would mean incline=up.
But as mentioned before I do not really remember how it is shown on StreetComplete (Has been some time since I chose it on the last stairs in my area).