The bubbly Spaniard claimed Olympic bronze in the women's 75kg at Rio on Friday, finishing behind North Korean gold medallist Rim Jong-Sim and Darya Naumava of Belarus who took silver.
"The first time I made the heart shape was when I won the European championships (2014) and people liked it. So I just kept doing it from there," she said.
"It's not for anyone special. It's for all the people who come and support me and who love me.
"I'm very communicative and I like to celebrate when things go well and when I'm happy I like to demonstrate it," the 31-year-old added.
Valentin, who wears mascara, earrings and a pink hairband when she competes has long been considered a "poster girl" for the sport which has been plagued by doping scandals over the years.
She's currently awaiting to have her fourth place finish at the London Games upgraded after medallists retrospectively tested positive for banned substances.
"To be honest I don't focus on what my rivals are doing. It's not my business," Valentin said when asked if she thought Belarusian silver medallist Naumava should have been allowed to compete.
The International Weightlifting Federation had wanted to ban Belarus from Rio over high-profile doping scandals but the International Olympic Committee was unable to complete retesting of samples from Beijing and London in time.
Valentin lifted 116kg in the snatch and 141 in the clean and jerk for a total of 257kg and third place on the podium Friday.
She said she now planned to upload a new photo to her popular Instagram account which has more than 45,000 followers.
"Yes, it will be with my medal," she laughed.