You should wonder if the astronomer has taken account of perspective.
A circular orbit, seen in perspective will appear to be an elliptical orbit, and if the brighter component is sufficiently more massive, it will appear to be at the centre of the ellipse. In this case Kepler's laws are not broken.
But if the astronomer has accounted for perspective, and the orbit is truly elliptical, then the two stars will move in ellipises around a common barycentre at a focus, and if the bright component is sufficiently more massive then it will be nearly static at a focus of the orbit of the less massive star. It would break Kepler's first law if the massive star was stationary at the centre of the elliptical orbit of the less massive star.