You should show (image of the general area), and tell us what we are looking at.

So far I'm guessing the top is foundation slab, the bottom is a finished porch.... if that is correct, I don't see the issues, but I'm sure by the time I get back to reviewing this thread the following recommendations will be made: 1. fire the contractor 2. tear it out 3. hire an attorney... etc.

What I can see is concrete in the curing process. It will change color while that happens. Once cured, the brush marks on the porch will look more consistent.

I'm not sure what the first photo is showing. The second photo appears to be a porch or maybe a walkway. Yes the broomng and edging are sloppy and it would bother me but that alone is not reason to tear it out. Assuming there will be landscaping at some point, and if that is a porch there will be other things to look at (chairs, planters, decorative something) the edging will lose the focus.

ditto what PPF said.