Not every music video needs to be a non-stop explosion of effects, crowds, and spectacle. Simplicity still has its place. It's really about serving the song in a memorable way. Nicki Minaj strips down a lot of the well-planned excess of her previous music videos to star in something quite lovely and simple for "Pills N Potions."
The track is a love song from a wonderfully mature perspective. The character in the song has removed herself from a less than ideal, possibly abusive, relationship but still has feelings for him. She knows that the relationship is bad (he convinces her to take those pills and potions), but she still loves him.
That is the crux. She misses him, but knows that the relationship is destructive. She won't go back. She's better now without him. It doesn't mean that she never had feelings for him or can't find some good in him; it just means she reached the point where she chooses to move on.
The video is just lovely. It's shot full frame (square) with a lot of close-ups of Minaj and the man in question. A rolling background of pastel smoke and metallic tears flood the screen over and over. These are spliced with shots of pills, bunnys, and, well, potions that are causing the warped perspective with distorted objects and flowing metal and smoke.