If you were to add walls to the right and left side of the stairs to the basement and then painted the floor at the bottom of the stairs to look like tile or add an area of carpet or tile there, it should help make it seem more like a part of the house. Right now it screams basement stairway. Also some added color in your mud room 'closet' ( pops of teal or yellow) and more organization should help it seem more friendly.