object/spring/29 matches the site

public static HumanMadeObject Spring_29_Measurement_of_Features()
{
    var spring = new HumanMadeObject()
        .WithContext()
        .WithId("https://linked.art/example/object/spring/29")
        .WithLabel("Spring")
        .WithClassifiedAs(Aat.Painting, Aat.TypeOfWork)
        .WithHeightDimension(74, MeasurementUnit.Centimeters)
        .WithWidthDimension(51.5, MeasurementUnit.Centimeters);

    var attrAssignment = new AttributeAssignment()
        .WithLabel("Unframed Measuring")
        .WithTechnique("https://linked.art/example/concept/measuring_unframed", "Unframed Measuring");

    spring.Dimension![0].AssignedBy = [attrAssignment];
    spring.Dimension![1].AssignedBy = [attrAssignment];

    return spring;
}

• Metatype classification The second argument classifies the first, not the object: WithClassifiedAs(Aat.Description, Aat.Statement) says this is a Description, and Description is a kind of Statement. The Plain C# form shows the nesting.
• Dimensions and physical description Each helper builds a Dimension with its AAT type, value and unit, or a classification with its metatype: height, width, colour, shape, page count, component count, file size, duration in days.

var humanMadeObject = new HumanMadeObject
{
    Context = ["https://linked.art/ns/v1/linked-art.json"],
    Id = "https://linked.art/example/object/spring/29",
    Label = "Spring",
    Dimension =
    [
        new Dimension
        {
            Value = 74,
            Unit = Aat.Centimeters,
            ClassifiedAs = [Aat.Height],
            AssignedBy =
            [
                new AttributeAssignment
                {
                    Label = "Unframed Measuring",
                    Technique =
                    [
                        new Type("https://linked.art/example/concept/measuring_unframed", "Unframed Measuring"),
                    ],
                },
            ],
        },
        new Dimension
        {
            Value = 51.5,
            Unit = Aat.Centimeters,
            ClassifiedAs = [Aat.Width],
            AssignedBy =
            [
                new AttributeAssignment
                {
                    Label = "Unframed Measuring",
                    Technique =
                    [
                        new Type("https://linked.art/example/concept/measuring_unframed", "Unframed Measuring"),
                    ],
                },
            ],
        },
    ],
    ClassifiedAs =
    [
        new Type("http://vocab.getty.edu/aat/300033618", "Painting")
        {
            ClassifiedAs = [Aat.TypeOfWork],
        },
    ],
};

Generated from the object the example builds: every property that is set, as object initialisers, with the vocabulary constants where a term is in the registry. The fluent helpers are a convenience, not a requirement; this form and the one as written produce the same JSON.