At the beginning of Chapter 7, Asher was informed by the mashpia that the Rebbe wanted to meet with him. To prepare for this visit, Asher began going to the mashpia's office every day after school to study the Torah and Hasidus. This shows that even though Asher didn't care what his father thought about his schoolwork or his artwork, he did care about what the Rebbe thought. He wanted to impress the Rebbe or at least not look foolish in front of him.
It was in the Rebbe's waiting room that Asher met Jacob Kahn, an artist who would soon become his mentor. The man drew a picture of Asher while he was waiting to be called into the Rebbe's office. When Asher emerged from the office after the meeting, Jacob Kahn quickly entered the Rebbe's office, leaving a picture of Asher on his unoccupied chair. Asher examined it, drew a picture of Jacob Kahn from his memory, and left it on the chair for the man. This shows that even though Asher didn't know that Jacob Kahn was a famous artist, he was intrigued by his work and in return wanted to show him some of his own ability.
Asher waited for Jacob Kahn outside the building, and their meeting sparked a new friendship. The man informs Asher that he is interested in working with him, but he does not start new relationships in the winter. He asks Asher to call him in March. I wonder if perhaps Jacob Kahn wanted time to devise a plan of attack. The Rebbe had wanted them to work together. He probably reasoned that if Asher must become an artist, Jacob Kahn would be the least harmful artist to work with. Jacob Kahn might have needed this time to figure out how he would teach Asher and still comply with their religion. I look forward to seeing how Asher's father will accept the idea of Asher working with another artist. Given the past history of his father, I don't think he's going to take it very gracefully.