The photo of her with short-cropped hair, bright red lipstick and a dark outfit with a plunging neckline, was posted on Thursday on her Twitter and Instagram accounts @xychelsea87, ABC News reported.
The 29-year-old Oklahoma native included the caption, "Okay, so here I am everyone!!", reports NBC News.
Manning was released early Wednesday from the US Disciplinary Barracks at Fort Leavenworth, Kansas.
Manning at that time was a 22-year-old Army private named Bradley Manning, reports ABC News.
The information she disclosed included low level battlefield reports from Iraq and Afghanistan, evidence of civilian deaths in Iraq and Afghanistan, Guantanamo prison camp detainee profiles and US diplomatic correspondence.
Former US President Barack Obama commuted her sentence to time served three days before he left office. Her imprisonment was longer than any whistleblower in US history.
Days after Manning was sentenced, she came out as transgender on August 22, 2013.
Army officials on Tuesday said Manning will remain on active duty in a special status after her scheduled release from prison.
In that status she will be unpaid, but will be legally entitled to military medical care.