OSIRIS narrow-angle camera image taken on 10 April 2016, when Rosetta was 30 km from Comet 67P/Churyumov–Gerasimenko. The scale is 0.55 m/pixel.
The unique viewing geometry is such that the spacecraft is positioned almost exactly between the Sun and comet, resulting in a near shadow-free view that reveals characteristics of the surface that cannot be seen otherwise.
More details via the OSIRIS Image of the Day website.