Assuming the lower opened box is for the viewing of the wiring for the picture and the flex contains an EGC , I do not see a violation.
See 314.22.
Since the Flex is for flexibility in this installation, It must have an EGC , 350.60.
An extension box could have been added to all of the flush mounted boxes and the LFMC could have connected to a KO in the side of the extension box(es), then the cover would have been ' just a cover'.
Looks like it could be a 'damp' location.
