Trébuchet is a red herring: a deliberate exception to the rule that Duchamp’s readymades relate, in some way, to the core trio of Nude Descending a Staircase, No. 2, Tulip/Morée, and Nude Descending a Staircase, No. 3.
Its apparent refusal of that pattern is itself purposeful. Trébuchet is meant to disrupt the viewer’s expectation of finding an immediate connection to the trio. The title literally tells us so: a trébuchet is a trap or tripping device.
The work is designed to trip us up. It interrupts the pattern just when we expect it to continue, making its own lack of an obvious connection the point.