"of the time" refers to the attempt of the artists to create an art piece that would reflect the contemproary culture.
Explanation:
Minimalist art forms refer to the use of either single or repeated patterns (mostly geometrical) in the creation of modern art piece.
The use of the term “of the time” refers to the activity of minimalist artist like Donald Judd to make an art of contemporary times. This was done by using the material which was at use contemporarily along with contemproary practises.
Donald Judd used to belong to the industrial or machine culture where most of the things were machine-made and not made by the artist himself rather industrial workers, hence he used bronze in the form of thin machine-made sheets which conformed to the machine culture.
These minimalistic art pieces later influenced the development of modern skyscrapers and many design firms.
C. Thomas Eakins
This painting is called “The gross clinic”