Based on the image I'd say it needs a little more contrast as said and also a very slight (about 1/4 of a degree) rotation anti clockwise so the vase and stem are more upright, they're very slightly slanting
There's not much that I can say that hasn't already been said to be honest.
I'd certainly like to reiterate the point about contrast between the subject and background, it needs to be much more distinct and not blend together so much.
I'm very much a self labelled perfectionist and as per the image rotation I'd say you're fine on that front, however, you've got a little bit of predominantly magenta chromatic aberration on the stem of the plant, which looks a little odd - from a technical point of view. From an artistic point of view I think it works quite well with the photo actually.
I suppose it really depends on the purpose of the photo, I can imagine it sitting on a wall quite nicely in a frame or on canvas, more so than I see it being used as a greeting card - but then maybe that's just my opinion.