The actual 'woman in the window' is actually in a painting in a shop window, before she appears to the main character - played against type by Edward G Robinson - as a reflection in that same window. It's a bit of a clumsy-clever title for a remarkably suspicious trick at the point the film takes off.
You wouldn't point to it as a genre establishing film on its own accord, and Robinson seems bumbling and out of sorts which may be good acting - or may be seen as a usually scary actor out of place.
Of the small ensemble cast Heidt, the corrupt ex-cop turned 'tail', and now a blackmailer, played by Dan Duryea, is the most convincing, perhaps because he is the only charecter with some snap and dynamism to him; the others often seem like they're sleepwalking. Perhaps the latter befuddlement is what happens in reality to 'normal' people is such a trapped situation, but it doesn't play well.
Whether you like the film or not, there's some interesting takes on it here (film showing 'free will' or not) and here, the latter including some musing on the role of artworks in the period in film:
"Elsaesser wonders if this indicates the revenge of cinema on painting or if the filmmakers are unconscious of the fact that the paintings they include are bad. (Could it be that they can only afford or find mediocre painters to execute them? Or could it be that because portraits of fictional characters in films are themselves fictional, they necessarily lack authenticity? Since the portrait is simply a prop, it does not need to be a genuine or great work of art.) His explanation is as follows: 'the mediocrity of these portrait paintings is less a matter of aesthetics and more a question of ontology… mediocrity being here the effect of a certain void or vertigo emanating from the portrait, or rather its pretence of a presence… it is bad… because of the multiple perturbations it brings to the narrative.'"
A good start at the budgeting point, unfortunately going into art-crit onanism. For what it's worth, and as can be seen in the still from the film (above) it's not a bad painting by any means and a better likeness of the subject than most of the filmic kind. There are plenty of 'great' paintings of people who are frauds, fakes and even actors in role*.
I would agree that generally most artworks in film (where they are created as solo or incidental props for those films) vary from low quality to risible. Other paintings, where the subject of the film is perhaps a painter or their oeuvre, the artwork can be of remarkable standard - I'm thinking of Bratbys in 'The Horse's Mouth'. A film for another discussion, another day.
*That's the great Ellen Terry as a truly terrifying Lady Macbeth by a chap called Sergeant.