My previous image (from 2015) gives an idea of what the window is like. It is large covering the full width and from about a meter from the floor to the ceiling. It would be difficult getting the whole window in even if I sat by the wall of the carriage; that would, however, eliminate some of the exterior on the right. Darkening and vignetting would help. And trying to eliminate the reflections would also improve the image.
OK, I do not know the window, so it was only a thought. The bar on its own looked odd as there was no context to show why it was there. Perhaps show one edge instead?
Maybe a polariser would help deal with the reflections? There will be an increase in exposure, so you might need to raise the ISO if the carriage is not well lit. Mind you, there should be plenty of light illuminating the scene with that amount of glass!