Oh something else we did in between those 2 photos - We switched her to a regular old single jointed snaffle bit, no twist or anything like that. In the first photo I believe it was an eggbutt snaffle and after trying a full cheek, loose ring, and d ring, I found her to be the lightest in the d ring snaffle.
The bar inside her mouth may be the same in all cases, but the way the cheek pieces sit and how they act on the corners of the mouth does make a difference, and something that works well for one horse won't necessarily work for another. You have to try them all out on your horse and see which she will respond best to.
And even her preference now may change from time to time as you go.
"The times when you have seen only one set of footprints in the sand, is when I carried you..."