Voisin is correct
1925 you are close but I have another date?
Not Smitsel but snutsel, I valid the coachbuilder
Not C3
Locked this puzzle for you barrett
I always assumed 'Smitsel' was a typo for 'Snutsel', but then I found this Chenard advertisement attached... I wonder if this was a typo, too, or there really was a Smitsel in Brussels? Now I see this Voisin is most usually described as by 'Snutsel' so you're probably correct.
I think the model is a C5. The event it was pictured at is 1926 - is this the year you have? I think the car itself was from 1925 but I'm not certain.