I am trying to work through Mostly Surfaces by Schwarz, but his explanations can be quite confusing. I am working on the section about the Euler Characteristic of surfaces. For instance he writes
It remains to consider the case when there is just one face whose boundary edges are paired in some way. We call this a gluing pattern for Σg. We say that the gluing pattern has a cross if we can find two pairs of glued edges (e1,e2) and (f1,f2) such that any line segment connecting e1 to e2 crosses any line segment connecting f1 to f2, as shown in Figure 3.4. In other words, the edges e1,e2 separate the edges f1,f2 from each other on the boundary of P.
Isn't this a picture showing that the two lines don't cross? I'm clearly not understanding something.