Hi David, My car has the same thing. The plastic lenses are missing. My understanding is there should be a red on a the rear side and a white one on the front. See this picture from Depanoto – https://www.depanoto-boutique.com/optiques-clignotants-lanternes-citroen-traction-c102x4057069
These are parking lights. There should be a switch for it somewhere. My car has 4 mystery switches on the dash of which I think 2 were for these lights – one for each side. As well as there being no lenses, there are also no bulbs and no wires so it’s all guesswork.
Chris