"Hygiene is very very important," the comedian captioned the post.
In the side-by-side photos, Rihanna, donning just underwear, held a shower head over her mid section while smiling.
In typically Celeste fashion, the mother-of-two mimicked the raunchy photo shoot with her own self-deprecating twist.
Celeste put on a pair of briefs and jumped in her shower, striking a pose with the handheld shower head.
She pulled a faux "sexy" face with her mouth wide open, similar to Rihanna's.
The satirical post garnered more than 300,000 likes in less than a day, with thousands commenting to share their amusement.
"Now THAT is a power shower!," one fan wrote.
"I definitely prefer to feel what you feel than what Rihanna feels," said another.
"She's done it again hahahaha caption though," another comment read.
Celeste has gained a mass following of more than 8million people thanks to her hilarious recreations of iconic celebrity photos on social media.
In early 2015, Celeste started the #CelesteChallengeAccepted, which has garnered her an impressive fan base including celebrities themselves.
She has parodied the likes of Emily Ratajkowski, Kendal Jenner, Kim Kardashian, Bella Hadid, Cardi B, Cody Simpson and Tammy Hembrow.
Celeste, who has become a bona fide Instagram star in her own right, has also made a name for herself on Australian TV.
She rose to fame on Aussie comedy series How Not to Behave and has appeared on Channel Seven's long running soap Home and Away, as well as All Saints, Neighbours and The Letdown.
Celeste is also a regular panelist on Have You Been Paying Attention? and has stood as a co-host on Studio 10.