Short front trigger

[Sparkitoff]

I've been looking at a few antique double-barreled shotguns that seem to have a short front trigger. In these examples (there are 3 from different time periods, Countries and specs) the front trigger is basically a flat, straight blade but the back trigger is the classic curved, full-sized face. What is the idea or concept of the short front trigger? They don't look broken off. They look odd and I just don't understand what was trying to be accomplished or accomodated.

 

[Sparkitoff]

This is an example...

 

[Brokennock]

I'm just guessing, but my initial thought is that it was done to make transitioning to the rear trigger for a second shot easier.

Second though that comes to mind is that it feels different, giving positive tactile reinforcement as to which trigger the finger is actually on.