Why was the Vera C. Rubin Observatory LSST Camera tested with a broccoli and a pinhole? The SLAC National Accelerator Laboratory video Vera C. Rubin Observatory LSST Camera (caution! annoyingly loud music, lower volume before playing) shows a Romanesco broccoli (which I'd assumed was a 3D printed mathematical surface of that name until I checked and found out that this is the name of an actual vegetable i.e. Brassica oleracea) as the object of a pinhole camera projecting its image on to the astoundingly large CCD array.
There are likely several advantages to using the pinhole rather than a well-corrected projection lens, is it possible to say what they are?
Is it also possible to elaborate on the choice of object for the camera?
See also:

slac.stanford.edu Sensors of world’s largest digital camera snap first 3,200-megapixel images at SLAC
BBC: Vera Rubin: Super telescope's giant camera spies broccoli
What is the LSST now? Where does LSST end and Vera C. Rubin Observatory begin?

Caution! annoyingly loud music, lower volume before playing:
https://youtu.be/qc_iscV1uA0
From the first article you linked:

Taking the first 3,200-megapixel images of a variety of objects, including a head of Romanesco – a type of broccoli – that was chosen for its very detailed surface structure, was one of these tests. To do so without a fully assembled camera, the SLAC team used a 150-micron pinhole to project images onto the focal plane.

Which implies:

the advantage of using a pinhole is that it allows the sensors to be tested without requiring the full camera to be assembled yet.
the Romanesco was chosen to test the sensors' ability to image an object with detailed structure.