I bet she felt a tug behind her Mickey, but to your credit it looks like you got your weight just about right. I could be wrong but it looks like the majority of the weight of the tractor was on the trailer axles, and the goose neck weight neither looks too light, not to heavy.
This is completely preference, but I get squimish over the years loading equipment on trailers. I typically BACK them on, and DRIVE them off, but that is me. Of course it changes the weight on the trailer too...to a worse position really if you do back it on. I would make a guess that those rear tires are loaded with calcium?
I have no intention of traveling from birth to the grave in a manicured and well preserved body; but rather I will skid in sideways, totally beat up, completely worn out, utterly exhausted and jump off my tractor and loudly yell, "Wow, this is what it took to feed a nation!"