As others have suggested, think about adding thicker lineart to the character, increasing the contrasts, and cutting back on details in the background.
For example, I would take out the cross hatching in the windows, It is making your character's face hard to read, and a viewer's eye is drawn to things with more detail, which really shouldn't be the windows. You can even fill them in with black or a dark color, and it will help your character's head stand out more.
Next I would pay attention to tangents, your character's head gets lost a bit because the window frame lines up with its chin, and a bit with the shoulders.
Think contrasts. A viewer's eye is also drawn to the areas with the most contrast, be that black on white, red on green, saturated on unsaturated, detailed on simple, etc. What you can do is change the color of the door so the horse tail stands out, maybe make it a green brown so it doesn't stand out, do the same for the wood around the windows, you can darken the building just a bit, but no the gray stone around the door, as it is a nice framing device for your character, desaturate the greens a bit, and thicken the lineart and darken the shadow coming from your character.