In as much as it has a collar and sleeves, it's a shirt. But the style of this is more like a smock and looks awkward if you button it up with nothing underneath.
Unbuttoned it's quite versatile and tanks to tees to oxfords are amped. Secondary colors in the stripes are a great guide for coordinating, and they cover a spectrum of flavors.
It's warm but lightweight, no structure so it takes the form of whatever is underneath. Unsure how it will hold up over time as it's a loose weave but no snags so far.
Still recommend as long as I don't see you wearing it.