Because it's clear whoever was designing for her reeeaaallly wanted her to be sexy / cis-sexually attractive to men.
And...that's...basically not cool. Of course, people will attract themsleves to literally ANY design of ANY character, no-matter what you do. I'm talking about magic cubes that talk to literal skeletons rising from the grave--some people are going to attract themselves to it. This cannot be controlled. However, deliberately designing for that is a complete other story that certainly can be controlled.
Black Leather:
Ah but of course, black leather mistress Bunnie! When turned partially into a robot AND being an animal, the skin=leather of another animal would be the first choice to wear. This is the one upon they got the "Robot Legs & 1 Arm" going that she ended up keeping. She needed to be "Bunnie the Cyborg", because she was never meant to totally be a robot--just enough that her pun-name is funny.
Top Right-
They LITERALLY write "Sexy" on the paper. No one is exaggerating or "reading into" what her intended purpose was, it's right there written on the page. The left image probably has a little bit of Darth Vader chest (buttons/panels) going on, and both of them have a leg that was clearly cut off. The cartoon/flesh leg would not fit in the spindly robot leg, so that one had her missing limbs twice. They also keep featuring the headset/mic , maybe to have her in an ops role?
Faced Away:
Ah, yes "This Awkward Stance", where it just happens to have her bent in such away that her butt is always on display/butt sticks up / out. The other note is Walks Funny but is Very Strong. That bit is fine/maybe the 'robot' procedure didn't go perfectly because it is stopped so she stomps around. This design more clearly has the "Robot" part as the shell that it ended up being/it's obvoius she'd fit in there. Note the half-lid/bedroom-eye and big smoochy lips.
Farthest Left:
Another one by someone else/not the main art for the page. This one gives the proportions that she ended up with, as well as the style of the legs and the arm as well as the configuration. The torso here was robotic too, but they dropped it. The head is...basically Babs Bunny from Tiny Toon Adventures. Who, of course...was modeled along side Buster Bunny to be in the exact stlye of Bugs Bunny. The head here was basically tossed out/which so much the better because of the tacky lips and ripped off Warner Brothers "WB" style.
When you saw her in the show, you never thought "oh that's Bugs in drag", because they clearly refined her more--adding bangs, changing the cheek tufts, giving dark rings over the eyes, and colored eyelids. The problem remained though that she never actually looked like a rabbit?
Never?
The only thing about her was the long ears. The tufty-face-bottom was always more cat than rabbit, and she had the same basic face structure of Sally, who's species was never mentioned in the show and was even argued about (Chipmunk or Squirrel) but both of those have a tail and she didn't. Of course, she didn't look like a Sonic character either, which is par for this course. Notice how the female characters always (end up) look like sexy small humans with funny heads but the male ones look like anything.