“A sort of jump-seat Mona Lisa”

Buddy Glass is leaving the scene of a canceled wedding. He sits with four other people in the back of a hired car:

Mrs. Silsburn smiled a smile that was at once worldly, wan, and enigmatic — the smile, as I remember, of a sort of jump-seat Mona Lisa.

J.D. Salinger, Raise High the Roof Beam, Carpenters (1963)

A sort of what?

In less safety-conscious times, the jump-seat was a familiar feature in cabs. Some jump-seats dropped down from the back of the front seat. Mrs. Silsburn and Buddy are sitting in jump-seats that face forward. Thus a “jump-seat Mona Lisa”: that’s what.

Related posts
A Salinger catalogue
A Salinger sentence
Another Salinger catalogue
“[D]ark, wordy, academic deaths”
Happiness and joy