New Delhi, Aug. 29 -- The two words Demi Lovato posted to Instagram on August 28 may be the most revealing statement she has made about herself in years. The first was "Hi." The second was "Bye!"

a jet ski, a string bikini in red, black, and yellow, open water. She turned 34 on August 20. The images drew thousands of fan comments, including one invoking her 2015 hit, "She's really cool for the summer," but Lovato herself offered nothing else. No milestone reflection. No gratitude post. According to Fox News, she let the photographs speak for themselves. Just: hi. And then: bye.

The brevity is the point. Lovato built a career on disclosure that was, for large portions of the 2010s, close to total. She spoke publicly about the 2018 overdo...