Consider Exhibit A:
a simple pleated skirt from Zara – here it looks pretty standard, a bit dull, and quite frumpy.
Like this, it would be fine to wear to school, but I wouldn’t feel particularly stylish.
Now take a look at Exhibit B:
The skirt has been hemmed 1 inch shorter, some heels and polka dots added, and what a more interesting outfit you have. I’m not sure that I’ll actually wear this entire combination, but it is cute for photos don’t you agree?