The phrase 'Kim Jong-il patriotism' was used to glorify the late leader after his 2011 death. The slogan was described by successor Kim Jong-un, as the 'crystallization of socialist patriotism'.
Images and references to North Korea's leaders, who are treated with almost god-like status in propaganda, are sacrosanct.
North Koreans are required to keep and carefully maintain portraits of former leaders Kim Jong-il and his father, Kim Il-sung. A special large, bold typeface is used when their names are printed.
The video purportedly shows Warmbier in a restricted area of his hotel in Pyongyang walking up to the wall before removing the rectangular poster which bears white lettering on a red background.
Warmbier, who went to the Communist state with a tour agency that promises travel to 'destinations your mother would rather you stayed away from', stayed at the Yanggakdo International Hotel.
CCTV shows the University of Virginia student entering a staff-only part of the hotel, which towers up from an island in the middle of the Taedong River.
Warmbier was at the end of a five-day group tour when he was stopped at the airport and taken away, according to the tour operator that arranged the trip.
In a statement last month, Warmbier confessed to 'severe crimes' against the state.
Warmbier entered the restricted area of the hotel in the early hours of Jan. 1, according to a time stamp on a CCTV image used as part of witness testimony to identify him.
That witness was Warmbier's North Korean tour guide, identified as Mr Byon, sources who recognized him confirmed after studying the footage.
The shirt and boots worn by Warmbier at the time along with his passport, mobile phone and an ID card were also given as evidence in the trial, the footage showed.
'When I got off work, there was nothing amiss,' a second witness, apparently a hotel staff member, told the court.
'But when I returned, I thought someone had deliberately taken the slogan down, so I mobilised security to prevent damage to it and reported it to the authorities.'
The court showed images on a flat screen showing efforts to match fingerprints from the banner with Warmbier's fingerprints.
Photos of the trial showed Warmbier marking copies of indictment and sentencing documents with red ink on his thumb.
As he was led from the court in handcuffs, Warmbier appeared to turn to Swedish ambassador to North Korea Torkel Stiernlöf, who was present at the trial, and ask him to 'keep working' on his case, according to the footage.
The United States does not have diplomatic relations with North Korea and is represented in consular matters there by the Swedish embassy.
North Korea has a long history of detaining foreigners and has used jailed Americans in the past to extract high-profile visits from the United States to secure their release.
He pleaded with judges in court Wednesday to 'please think of my family' and prayed for God to 'please save this poor scapegoat' before the sentence was handed down.
The White House condemned the sentence as 'unduly harsh' and demanded Warmbier's 'immediate release' from jail on humanitarian grounds.
US State Department spokesman Mark Toner said: 'Despite official claims that U.S. citizens arrested in the DPRK are not used for political purposes, it's increasingly clear from its very public treatment of these cases that the DPRK does exactly that.'
However, such a release appears unlikely as President Obama signed an executive order late Wednesday ordering tough new sanctions on North Korea relating to alleged nuclear tests carried out in January, and a ballistic missile test the following day.
'The U.S. and the global community will not tolerate North Korea's illicit nuclear and ballistic missile activities, and we will continue to impose costs on North Korea until it comes into compliance with its international obligations,' the statement concluded.
The president's order allows for U.S. implementation of sanctions approved by the United Nations two weeks ago.
Last month, North Korea paraded Warmbier before the media in Pyongyang, where he tearfully apologized for attempting to steal the political banner.
According to Warmbier's statement on Monday, he wanted the banner with a political slogan on it as a trophy for the church member, who was the mother of a friend.
In his comments, Warmbier said he was offered a used car worth $10,000 by a member of the church.
He said the church member told him the slogan would be hung on its wall as a trophy. He also said he was told that if he was detained and didn't return, $200,000 would be paid to his mother in the form of a charitable donation.
Warmbier identified the church as the Friendship United Methodist Church, which is in his hometown of Wyoming, in Ohio.
Warmbier told reporters in Pyongyang that he had also been encouraged in his act by the university's 'Z Society,' which he said he was trying to join.
The magazine of the university's alumni association describes the Z Society as a 'semi-secret ring society' that was founded in 1892 and conducts philanthropy, puts on honorary dinners and grants academic awards.
Warmbier said he accepted the offer of money because his family is 'suffering from very severe financial difficulties.'
U.S. tourism to North Korea is legal and virtually all Americans who make the journey return home without incident.
Even so, the State Department has repeatedly warned against travel to the North. Visitors, especially those from America, who break the country's sometimes murky rules risk detention, arrest and possible jail sentences.
Young Pioneer describes itself on its website as providing 'budget tours to destinations your mother would rather you stayed away from.'
The agency, based in China, also has tours to Iran, Cuba, Turkmenistan, Iraq and other former Soviet countries.
- Daily Mail