Little window scene.

A little scene.

what is it you’re testing here? You could try and make the curtain translucent, so there’s a bit of shadow from the planter behind it, and add some glow through the compositor…
Other than that, it’s almost real looking, aside from the red wall paper seam, and what’s at the very bottom edge in the middle?

Quoted for agreement.

I find the render to be pretty realistic, but because of the curtain it looks more like a detail from a larger composition than a finished piece. I would extend the scene a bit if I were you.

Or you could have a gust o wind blow the “soft body” curtain