henra,
The photo you have is of a CVR (see the label on the recorder electronics behind the CSMU) - however the CSMU on the FDR carried by AF447 is similar in appearance (cylindrical).
RR_NDB believes that the CSMU should be cubical and with rounded edges. (as in his earlier post where he gives all the technical details on the SSFDR and CVR) But this is incorrect for the model (4700) of SSFDR carried by AF447. The publicly-available data sheet from Honeywell shows only diagrams for different (presumably earlier) models of SSFDR. As I mentioned before, the 4700 model FDR carries a cylindrical CSMU.