Quality issues rejection.

In a nutshell DPI = Dots Per square Inch and is only important when printing. It doesn't matter for screen viewing. The dowloader can decide what value to use.

Changing the "dpi" value (which indeed is a ppi value) does not change anything with the picture and is a nonsense parameter in photography (that is not exactly the same in print!).  Out of habit, that parameter should stay at 200 to 300 ppi, but as said, it does not change, improve or worsen an image. 

The fist asset is underexposed. I suppose that you lowered the whites to get rid of the overexposure of the upper part.

The second has indeed a leaning horizon, but it could also need more contrast in the sky.

The second image has a leaning horizon. The third image needs to be dehazed, add more contrast and remove the branches intruding from the sides. The last image also has a leaning horizon and that dark mass in the upper right corner should have been removed.