The real problem with this, apart from the inherent ambiguity of English, is that the axes are never defined so the graph can take any form you want. Steep (as

The real problem with this, apart from the inherent ambiguity of English, is that the axes are never defined so the graph can take any form you want. Steep (as in climbing) usually denotes effort or adversity - a point which may be missed by non-native speakers - hence the apparent contradiction when you add your own labels/axes and interpretation to the graph.