A group of about 20 family and supporters packed Perth Magistrates Court on Friday for Brodie Jake Dewar's appearance via video-link from Hakea Prison.
The 20-year-old is accused of attacking Mr Picton, 36, in Northbridge, in Perth's inner city, in the early hours of December 27.
Mr Picton, who has been lauded as a brilliant political tactician, died in hospital several weeks after hitting his head on the pavement during the incident with Dewar.
His death triggered an outpouring of grief from his family, friends and colleagues, as tributes flowed from the prime minister, several premiers and business leaders.
Mr Picton had advised state and federal politicians, and helped guide WA Labor to a landslide 2021 election victory.
Dewar was originally charged with grievous bodily harm over the incident that was recorded on CCTV, but this was upgraded to manslaughter after Mr Picton died.
Magistrate Benjamin White allowed Dewar bail on Friday for that charge, saying the risk the accused potentially poses to the community could be mitigated with conditions.
But he was not convinced there were sufficient grounds for bail to be granted for a lesser charge of acts or omissions causing bodily harm or danger to any person, which stems from an incident involving Dewar and another man on Christmas Day in the Perth suburb of Kalamunda.
During the bail applications, the court heard Mr Picton was ejected from the Paramount Nightclub due to intoxication before Dewar allegedly attacked him on the street about 45 minutes later.
In the hours before that, Mr Picton repeatedly grabbed Dewar's 18-year-old cousin around the waist and made unwanted advances towards her, according to defence lawyer Simon Watters.
The young woman, Dewar and others in their group repeatedly told Mr Picton to stop and go away, but the unwanted attention continued, the court heard.
Mr Picton's advances continued on the street after the venue closed, amid numerous attempts to dance with the young woman before he was allegedly attacked.
Mr Watters described Mr Picton's behaviour as "belligerent and entitled" and said his "moral compass pointed due south" on the night.
Dewar and Mr Picton came face to face several minutes later, after the older man made another failed attempt to engage with the young woman outside a fast-food restaurant.
Mr Picton had his left hand in his pocket and was not acting aggressively, according to a police prosecutor, who cited CCTV footage.
He slowly lifts his right hand and takes a puff on a cigarette before Dewar allegedly struck him in the face, and he falls to the ground, hitting his head.
His hand only came out of his pocket once he was lying on the ground.
Minutes earlier Dewar was allegedly struck on the head from behind and involved in a scuffle with another man not related to the incident with Mr Picton.
Mr Watters suggested Dewar may claim he was defending himself against Mr Picton and the man involved in the December 25 incident, and that he pre-emptively struck both of them.
This was rejected by the prosecutor while opposing bail, and the court heard Dewar was recorded on body-worn camera admitting the alleged Picton incident in the minutes after it occurred.
Despite granting bail for the manslaughter charge, Mr White said the cases against Dewar were strong, and it didn't appear there were any obvious defences.
Dewar was remanded in custody to appear in Stirling Gardens Magistrates Court on February 18.
