Most of the magic happens here

Check out v1, v2.1 and v3 commits

v1 is a simple <img src="..." /> w/ gradient border, but without white sub-border (1 node)

v2.1 is a div, :after & backgroundImage (2 nodes)

v3 is an img in 2 nested divs (3 nodes)

Instagram itself draws gradient border in canvas.

This project was bootstrapped with Create React App.