For comparison, here's a top UK show bulldog.
And a closer look at those profiles..
Now when I first saw the pix of Mabel I assumed she was a cross, but it turns out she is KC-registered and was bred by a KC Accredited Breeder.
So which do you prefer? While you're making up your mind, here are some more pix of young Mabel (about a year old now) romping in the park... Yes, a warm day and she isn't panting.