The first thing that caught my eye about this painting by Van Eyck was the contrast between the husband and wife, or more specifically, man and woman. The man is in dark colored clothing and covered by a poncho like attire, while the woman is presented in much lighter colors of blue, green and white. The woman stands out much more in comparison to the man and their colors could symbolize light and dark, or good and evil.
Another thing that caught my eye was the use of lighting. On the left, you can see a window and through the window you can see that it is during a sunny day because of how bright it is painted. The light of the window casts a shadow of the woman on the wall behind her, which can be seen clearly on the right. Objects that are not in front of the window are darker because they are not exposed to the light.
The detail of this painting is quite great because of the artist's attention not only to lighting and shading, but also to objects and placement. The chandelier and mirror are perfectly visible in the center of the man and woman. At first, I was not sure whether the object below the chandelier was a mirror for certain until I zoomed in to get a closer look. I realized it was a mirror once I saw that the backsides of the man and woman in the same position were visible. This blew my mind. Eyck went to such great lengths to capture reality in this moment right down to the reflection in a mirror! Even the lighting from the window is captured in the reflection and the reflection is presented in like a, "fish eye" perspective.