Mincome != Basic Income. Under Basic Income, everyone gets a fixed amount unconditionally. Any extra income you get on top of that is yours to keep. So you get

Mincome != Basic Income. Under Basic Income, everyone gets a fixed amount unconditionally. Any extra income you get on top of that is yours to keep. So you get the $2800 from the government, then get a job for that $1200 (from the grandparent's example), so now you have $4000 in total. Mincome worked differently from this, but the OP talks about Basic Income, which just gives a fixed amount to everyone.