Answer by Shubham Chandel:
It's not the resolution, it's the background upon which the photograph is placed doing all the magic.
The photograph is in .format and all that magic lies within the construction of photograph.
As seen above, a .png format unlike others like .jpg, supports transparency, ie. a .png photograph can have some transparent pixels.
If placed upon a black background, the pink portion of lips and nails combines with the back background, which overlaps to produce a maroon effect. Same will be the case with any other background.
You see, there's no rocket-science behind this. just plain PNG format !