While his predecessors' portraits are all across the country, Kim has long been styled as a successor rather than a leader in his own right, the BBC reported on Tuesday.
His role has seen a gradual change over time though, very much helped by a string of international visits in 2018.
The huge new picture was on display during a visit by Cuban President Miguel Díaz-Canel.
Older pictures of Kim's were photographs, not paintings, or unofficial fan art.
"That a painted portrait of Kim Jong-un has appeared in this style is a strong hint that the regime could be beginning to take steps to develop the Kim Jong-un personality cult," Oliver Hotham, analyst with NK News, told the BBC.
The style of the painting is so evocative of the ever-present portraits of the older Kims, that "North Koreans will certainly understand the symbolism of this move".
Kim moved to the helm of the country rather abruptly when his father died unexpectedly in 2011.
He was relatively inexperienced and had not yet been built up as a future leader.