Hang a nice horizontal piece of art below it I often hang art in DRs lower than in other spaces since the art is viewed sitting down.I always love drapes in DRs and bedrooms so maybe add those too.

You already have the wall with the fireplace - you don't need to paint an accent wall. The rooms pictured below don't have the same kind of window yours does, but the art really perks up the room. Dining rooms can be kind of boring - it's a good place for art - whatever you like.

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