Buying a laptop just for mining? I hope not. They cost more, perform worse and age faster than a desktop
and can't be expanded.
Even part-time mining on a laptop is a bad idea. Make sure you have extra cooling.
Mining over wifi also has its issues.
If you're doing it for money, you'll lose. A single 1660ti, especially a mobile one, won't make
enough revenue to be significant, let alone profitable.
If you're doing it for fun you're better off with an old desktop with a decent GPU.
Pretty sure he just didn't buy it for mining primarily. Most likely he is a gamer and bought a gaming laptop (jugding by the GPU included) and just wants to mine when the laptop is not in use.
I know that CPU mining on a laptop is a bad idea, but GPU mining on a gaming laptop? Might not be so bad as long as he removes the battery to prevent it from overheating and leaking and exploding.