Two different deals for the same card.
There are more goodies with the $140 card.
to add a bit more ... the annual fee for the basic card is $60, UA is basically saying they'll give you that for free and if you want the plat card instead go for it, but you are now responsible for the fee difference. For the record - I would cancel the plat immediately if UA did not cover the annual fee (I'm grandfathered in for the full rebate).