I've done an edit with a few suggestions:

I agree that the shading under the desk didn't work. Although your light source is in the top right of the image, these desks are usually enclosed at the back so there shouldn't be any highlight visible. A more skilled artist than me would find a way to show some light creeping in under the bottom of the board at the back of the desk, which I think would add to the atmosphere and story as you'd get the sense of the light from the monster "invading" the woman's hiding space, showing that she's in even greater danger.

Some other things I've addressed:

I made the lighting more dramatic, firstly by putting a big lit area onto the floor projecting away from the door and, secondly, by getting more use out of the orange shade to highlight parts of the desk to make it pop more.

The monitor, keyboard and mouse all seemed very small. You could probably make them even bigger than I did. Apologies if this picture isn't meant to be set in the 90s–mid-00s, but it looked like a CRT monitor to me in your image so I rolled with it.

The areas that would be darkest on the woman's face (open mouth, pupils) were the lightest in your image, so I've reversed that and got more of the mid red in the face to allow for more defined shadow, so there's visible structure to the face.

Her chest was very well defined but clothes tend to soften out the form of the body (unless specifically designed to emphasize it). Given that this is an office setting, I've tried to shade the top so that it's less revealing but also gives a sense of the forms underneath.

Some other thoughts:

The lighting isn't exactly accurate in my edit for the sake of being able to shade the character better. Think of this as being lit more like a film, where there's a separate light off the canvas, to the right and towards the viewer, to give more definition to the character. Again, a more skilled artist could probably convey her expression and character just using the single light source visible but I am not that artist!

I found a couple of areas in the original a bit hard to read. I think the object behind the desk (by the door) is a table with a plant and some books on it, but I'm not certain. Might be worth looking at how it's drawn again to clear it up, but it could also just be me. The object on the woman's desk to the right could also be either a plant pot or a desk tidy with pens in it. My assumption was plant. Finally, I'm struggling to understand the monster itself. Is it a skeleton holding a torch, or is the light from a large eye? I think simplifying the lines in that area would make your intention clearer.

I'm not sure you're getting as much mileage from that one pixel as you could given that it's not all that distinct from the orange shade around it. I don't have a suggestion there because I need a lot more practice with colours, but perhaps you could switch the red for a purple or blue, dull down the orange slightly and see if the pixel jumps out more. It's also not clear what the pixel is conveying in the scene, which goes back to my earlier point about the nature of the monster being unclear. Is it the centre of the light source, or is the pixel itself the eye?

Hopefully that helps a bit! You've got an interesting scene with good atmosphere already, and I always like a picture that captures a bit of a story which you've done very well so far. Looking forward to seeing the next version!