Grunt.js changes file path by itself?

Question

HTML

Good afternoon!
The situation is this - Grunt is connected with less.js. There is a div on which I wrote background-image: url('img/header-banner.png'). Folder structure:
dist
---css
---js
src
---css
---js
img
etc.
The problem is that the image is not showing. I put the tag in html, everything is fine.
I can not understand what is the problem and how to prescribe the path now?