Serena Williams is serving mind tricks in the gym.

After giving birth over the summer, the tennis star has returned to her gym groove. Over the weekend, the mom of two posted a new snap of her targeting her core in a floor exercise as her 5-year-old daughter, Olympia, sits in front of her, as reported by Parade.

But the picture threw many people for a loop in an optical illusion at its best. “Olympia watching me try to get my ab muscles working again,” she wrote in the caption of the post. “Here comes fitness!”

In the snap, Williams is seen lying flat, face up on a fitness mat, while her hands are on her hips and feet planted on the ground. As her mom is positioned on the floor, Olympia’s beautiful head of curls is directly positioned in place of Williams’, which has caused many of her followers to think twice, as we did—still confused? See for yourself.

After posting the image, the comment section exploded with bewildered fans. “I know I’m not the only one that was looking for Olympia?” said a user whose comment has garnered over 800 likes. Another user chimed in, “Had to look twice to figure it out.” That comment has been liked 458 times.

Her hubby, Alexis Ohanian, simply adored the moment. “Love this photo,” he wrote in the comment section.

In August, the happy couple welcomed their second child, Adira River. Days later, an adorable photo of her holding her baby sister while she slept was posted to Olympia's personal Instagram account.