Your picture can not be viewed. It brings up a login screen for Yahoo. You could trying posting it here directly using the “Img” button and the picture’s URL.
As for what you described about the device, it is not extremely uncommon to see a ceiling mount device on a wall. The store Ikea seems to always do this in their restrooms, as well as Macy’s. The strobe coverage of the ceiling mount devices won’t be as effective as if a wall-mount device was used, but there doesn’t seem to be anything wrong with it.