Linus is a bigwig. Linus has a big head, and a big office to match. But often Wilder shoots it so it looks even bigger—like aircraft carrier big.
For instance, when Sabrina comes into Linus' office for their last date, she's shot way across the room, isolated against the doors. At the board meeting in his office, Linus is shot from across the table, isolated against the windows.
Wilder frames shots of the office this way to show it's big and lonely and ominous. In a lot of ways the office is the enemy of the picture; it's Linus' business that interferes with Linus' love. So the office is a giant telescoping trap.