Why painting in court

Courtly styles throughout the Song and Yuan period were characterized by technical finesse and close observation. Court artists spent part of their time copying old masterpieces, a practice that served the practical purposes of preserving compositions but also helped maintain high technical standards. The fan painting below of an imaginary palace is an example of the sort of fine-line, highly detailed and exacting painting court artists could make.

Why depict something as complex as a multi-story palace building on a small fan? During the years of Mongol rule in the Yuan dynasty, court sponsorship of painting continued, but at nowhere near the levels of the previous dynasty. The Mongol rulers did continue the tradition of official imperial portraits, however. Except for their Mongolian clothing style, the portraits below of Khubilai Khan and his empress-consort Chabi follow the same conventions of pose and idealized likeness as their Han Chinese counterparts of the Song dynasty.

Or Is That Martha Stewart??? And it's not the first time court sketches have been mocked online - sketches of pharmaceuticals CEO Martin Shkreli and NFL player Tom Brady have also seen their fair share of memes and comments. Tom Brady's DeflateGate court sketch.

Is it an epic fail or nah? But actually, court sketches play an important role in modern trials - and the artists say there's a lot more to the job than just sketching a likeness. It's often the only way we can get a visual insight into how a trial looks.

While cameras are allowed in many US courts and some trials are even televised , cameras are banned from federal courts. Instead, court artists are used to capture key moments of the trial - including a speaker's expressions, emotions and body language. Watch: The art of the court trial. Artist William Hennessy Jr, who has covered high-profile trials including those of Chris Brown and Mike Tyson, says it's a challenge because "nobody's there to pose for you".

Celebrity court cases are particularly tough because "the more people know the individual, the more critical they're likely to be - so the pressure is on for you to get the likeness accurate". Jane Rosenberg was behind the sketches of Tom Brady that went viral. After they sparked dozens of memes online, she apologised for "not making him as good-looking as he is" and said she had been "under a lot of pressure to work very quickly". She did try again - and people were pretty happy with her follow up effort - with one newspaper saying she had nailed it.

Sketch of US footballer goes viral. Christine Cornell, a court artist who sketched the Bill Cosby trial, agrees the job involves "hideous deadlines". She says the least amount of time she's had to do a sketch is about half an hour, although "an hour is more typical". As if the time pressure isn't bad enough - sometimes courtrooms are so crowded the artists can hardly see the person they're meant to be drawing.

In those cases, she says, court artists need to be good at capturing a person's face from quick glances. In the case of the Bill Cosby trial, she was designated a seat behind a pillar - which she describes as "drawing under the very worst of circumstances".

Luckily, she had practised drawing him during the pre-trial hearings where she was allowed in the jury box - "so I could draw him very well with just brief glimpses". If you think US court artists have a tough job, spare a thought for their cousins across the pond.

In the UK, most courtrooms ban cameras - and artists are prohibited from sketching people in court as part of the criminal justice act. The artists have to make notes during the hearings - and then draw their impressions from memory. Julia Quenzler, a court artist in the UK, told the BBC in a previous interview that she would write brief notes about the hair, facial features, clothing and body language of the main players, before scuttling off to the press room to commit the image to paper.

Many judges are against the idea, arguing that that it will change how people behave in court, intimidate witnesses, and make judges and lawyers more likely to perform for the cameras.

Others though argue that cameras would allow more transparency - and give the public a better insight into how the judiciary operates. A day in the life of a court artist. When can you take notes in court? Ms Cornell argues that "photos are very unfair in the courtroom, where there's supposed to be a presumption of innocence". Sketches are less intrusive, and capture "a combination of moments rather than one moment", whereas a photo or still of someone's expression can be taken out of context, she says.