For Mandell - a Bala Cynwyd artist who has created mosaics for private collectors and public institutions such as Citizens Bank Park, Lower Merion High School, and the National Liberty Museum - interpreting dozens of masterpieces with broken bits of tile and gemstones was a "crazy challenge."
It wasn't the first time he has rendered Matisse in miniature. Earlier this year, Mandell created another Barnes mosaic, showing the opposite end of the Great Room - complete with the museum's idiosyncratic founder, Albert C. Barnes, resting on a bench - for real estate developer Lenny Feinberg, who financed the film The Art of the Steal. The 2009 documentary recounted the decades-long spat over the museum's finances and the controversial decision to move it to Philadelphia.
Feinberg, who also studied at the Barnes, said he commissioned the piece after working for two years on the movie.
"Dr. Barnes would sit in the main gallery and take inspiration," he said, "and I wondered if Jonathan could capture that."
Mandell said he started by researching pictures of the Great Room, then came up with the perspective and decided which paintings, or pieces of paintings, to include. For Feinberg's 6-by-4-foot piece, he had to re-create Georges Seurat's The Models, a small but luminous canvas showing models in his studio with a partial painting of Sunday Afternoon on the Island of La Grande Jatte pinned to the wall behind them - two masterpieces in one.
That meant reproducing in miniature the exceedingly detailed La Grande Jatte, which was the inspiration for the Broadway musical Sunday in the Park with George.
Because the rendering of Grand Jatte in The Models painting is set on an angle, Mandell's likeness is distorted as it goes back in space.
"I had to make everything look recognizable," he said. "The challenge comes in deciding what details can be omitted and which are necessary to include in my mosaic version."
To show the golden luster of frames of the era, Mandell used the gemstone golden tiger's eye. The chandelier is rendered in quartz. Metal door hinges and brackets that hang amid the paintings - part of Barnes' unique collection - are made of metallic tile.
"It's brilliant," said Feinberg, who hung the mosaic in his living room.
Milgram's picture includes Cezanne's Nudes in Landscape and Renoir's The Artist's Family, as well as Picasso's The Peasant, and Seated Riffian by Matisse. Standing in the gallery are the couple and their two children, Lauren, 13, and Caroline, 9.
"I enjoy how he makes the characters in his mosaics more than static, posed figures," Milgram said. "They tell a story."
Though tiles are opaque, Mandell creates an illusion of transparency and even motion, as he did with the Kobe Bryant mosaic gracing Lower Merion High School.
But even he acknowledges that the Barnes pieces "were pushing the envelope of sanity with what you can do with pieces of tile and glass."
The practice of making pictures out of tiny shards of stone may be nearly as old as civilization itself, yet the process hasn't changed much. Unlike paintings, which can be altered with a few brushstrokes, mosaics must be carefully planned, with each pebble-size piece painstakingly sorted by color, shape, and size and then attached with adhesive.
Mandell, who graduated from Lower Merion High School, became interested in mosaics while earning a master's degree in sculpture at the University of Pennsylvania.
"It was sculpture, painting, and drawing coming together in a craft medium," he said in his converted garage studio behind his large stone house.
He created a niche doing work for synagogues, but strives to build a broader audience. In 2004, when the Phillies commissioned four bronze statues for their new ballpark, he pitched his mosaics as an interesting alternative and won commissions for two large pieces.
One is a 6-by-4-foot portrait of Jim Thome done in ceramic tile and red-stained grout to create the uniform's stripes. The other is an 8-by-6-foot stadium scene studded with dozens of figures and at least 25 types of stone and materials.
"A lot of tweezer work," Mandell said of how he does his ballpark scenes, some of which depict crowds of hundreds. It's one of his recurring themes, along with bars and restaurants, almost always expressed with a touch of whimsy.
Mandell's latest commission is an 8-by-6-foot history of Bryn Mawr Hospital, but the project is on hold until the hospital raises the $50,000 fee.
For that one, Mandell will have to render highly detailed scenes, such as doctors performing arthroscopic knee surgery.
"It will be a real masterwork for me," he said, "just like the Barnes scenes."
Contact staff writer Kathy Boccella at 610-313-8123