The EV figures are somewhat atypical in that they are for the other player(s) in the hand, not the one taking the action you're analyzing
When viewing bluff EV in % pot, we use the pot size before the other player had bet/raised. Meaning if they bet 5bb into 10bb, our call EV would be 150% vs a bluff, and -50% vs a value bet
Call EV is the average EV of bluff catching, always with a hand that only beats "bluffs" and nothing more
On flop and turn, the bluff EV of a raise (viewing a BF spot) should always be negative in theory, since if it was positive you could raise with any 2 cards. You can hover over the indicator to see the exact GTO bluff EV