Think of a world with two people. One rich one poor. Both get checks for $500, but the rich persons taxes go up by $1000 to pay for the program. The net effect is different for the two people.
Now in a more realistic setting with a range of incomes, the tax burden of UBI increases in a persons wealth. When you take the net of UBI income minus UBI taxes you get a progressive tax scheme. This means it is not a transfer in the way economists talk about transfers. You still have an effect where people get "punished" with higher taxes as their income goes up.