Shouldn't "Ordered Content" have a leading plus in Figure 3.4?

[lucabalsanelli]

In "3.2.2.1. Mapping Key Order", the key order is clearly defined to be a serialization detail. "Figure 3.5. Presentation Model", concerning mapping nodes, rightfully depicts +Ordered Content (the plus indicating that it is a serialization detail).

However, "Figure 3.4. Serialization Model", concerning mapping nodes, depicts "Ordered Content" (without the plus).

Why is that? Am I missing something?