How do you light a corporate interview in a room too small for a proper setup?

One light, one small room

One LED panel through a softbox at about forty-five degrees off the camera, and the window behind the subject left to do the backlight. The window blows out, and that is the trade: it buys separation that a small room otherwise cannot give you, without needing a second light or anywhere to stand it.

The setup

One LED panel, diffused through a softbox, as the key.
Roughly forty-five degrees off the camera axis.
The subject placed with the window behind them.
The window used as the backlight rather than curtained off.
The window itself allowed to blow out.

Why the window stays open

The instinct in a small room is to close the blind and control only the light you brought. It is the safe choice, and it throws away the one thing the room is offering. A subject in a small office has a wall immediately behind them, so nothing separates their shoulders and hair from it and they sit flat against the background. A window behind them fixes that with no second light, no stand, and no floor space — which in a room this size is the binding constraint, not the budget.

Why it is allowed to blow out

Holding detail outside means lifting the interior to daylight level, which one panel in a small room cannot do. That leaves three options, and only one of them is any good.

Close the blind: the separation goes, and everything has to be lit from what you carried in.
Expose for the view: the face goes dark, which is the one thing an interview cannot afford.
Expose for the face: the window goes white, and the subject is correct.

A blown window behind a properly exposed face reads as a window. It does not read as a mistake. The highlight was never recoverable in that room, so spending it deliberately costs nothing that was actually available.

What the forty-five degrees is doing

Key at roughly forty-five degrees off the lens axis puts a shadow on the far side of the nose, which is what gives a face structure on camera. Straight-on light flattens it. Much further round and half the face disappears, which suits a documentary subject more than a corporate one.

Why the softbox matters more than the angle here

In a small room the wall behind the subject is close enough to catch everything. A bare panel throws a hard-edged shadow onto it, and that shadow tells the viewer exactly how little space there is. Diffused through a softbox, the shadow edge softens enough that the wall stops announcing itself — which is most of what makes a cramped office read as an ordinary room on camera.