"I don't know how tall he is, but he looks short," she said of Jimmy, who is actually 6"1.
Despite only watching one episode of the latest season, the 35-year-old said Jimmy isn't the sort of man she would normally gravitate towards.
"I'm kind of at the point of my life where I know if there's a vibe [with a man]. But he's not for me, no," she said.
"But that doesn't mean he's not a decent guy. He's just not my type... He's just not for me, no."
Keira also suggested the women on Jimmy's season don't find Jimmy particularly attractive either.
"I don't think that many of the girls on this season really liked him, did they?" she laughed.
Keira found love with Bachelorette star Jarrod Woodgate on Bachelor In Paradise in 2018, but the couple parted ways for good in mid-2019.
In July last year, the blonde beauty started dating Love Island Australia's Matthew Zukowski, but the pair broke up in March.
Matt has been rumoured to have moved on with his co-star Anna McEvoy, which Keira claimed was a manufactured relationship for fame.
“They aren’t dating they are pretending to be together as they want to get exposure for some podcast they are doing,” she said.