slow art
n. Art created or presented in a way that encourages unhurried viewing and deep contemplation; a work of art that unfolds over a long time.
Since I first encountered Boggs's paintings, about two decades ago, I have slowly become a convert and a great admirer of his very quiet and profound meditations. Stillness and silence are among the most notable characteristics of his art, with every element distilled, ordered and beautifully observed. So much art today screams for attention, it is noisy and gimmicky and ultimately quite ephemeral. Boggs's art is what you could call "slow art", which is there for contemplation, meditation and is intended for the long term.
—Sasha Grishin, “Peter Boggs: Interiors and the mystery of light,” The Sydney Morning Herald, April 03, 2015
Indeed, a number of museums now offer "slow art" tours or days that encourage visitors to take their time. Rather than check master works off a list as if on a scavenger hunt, Sandra Jackson-Dumont, who oversees the education programs at the Metropolitan Museum of Art in New York, said you can make a sprawling museum digestible and personal by seeking out only those works that dovetail with your interests, be it a love of music or horses.
—Stephanie Rosenbloom, “The Art of Slowing Down in a Museum,” The New York Times, October 09, 2014
The series is unique for the sheer expanse of the time it covers, but it's only one example of the way other long-term or "slow art"—where either the creation or reception of the work is a purposefully slow process—is taking root across our culture.
2004 (earliest)
We have had a gutful of fast art and fast food. What we need more of is slow art: art that holds time as a vase holds water: art that grows out of modes of perception and whose skill and doggedness make you think and feel; art that isn't merely sensational, that doesn't get its message across in 10 seconds, that isn't falsely iconic, that hooks onto something deep-running in our natures.
—Robert Hughes, “A bastion against cultural obscenity,” The Guardian, June 03, 2004
If I had been practicing "slow neology," I'd have posted this phrase last week in anticipation of Slow Art Day, which happened last Saturday, April 11, 2015. *Slaps forehead* You can catch up on all the events at your leisure by visiting the Slow Art Day website.

Also, for the record, I should note that New York's P.S. 1 Museum (now called MoMA PS1) ran a exhibit called "Slow Art: Painting in New York Now," back in 1992.