Who are the Tal Shiar, and what bearing could they have upon 2 Romulans living with Picard and aiding him in wine-making back on Earth.
The Picard: Countdown comic book recently revealed these 2 figures to be Zhaban and Laris, former of the Tal Shiar who fell in love against the laws of their order but were rescued and sheltered by Jean-Luc. The Tal Shiar were first mentioned in Romulan Empire by any means necessary, and the Tal Shiar had free reign to suppress insubordination, quell rebellion, and preempt invasion. Due to their autonomy and power as an intelligence organization, the secretive Tal Shiar were often at odds with Romulus' own military - perhaps not helped by the Tal Shiar's considerable resources and cutting-edge experiments with technology stolen from the Borg.
Although the Tal Shiar were mentioned earlier, they don't become a recurring presence in the Section 31. Although the Federation's secret service may not be quite as ruthless and intimidating as the Romulan variety, both organizations highlight a hidden distrust between races in the Star Trek universe, as well as a desire to maintain power at the expense of moral principles.
Romulus as a planet is no more in Star Trek's prime timeline, but it's highly likely that the Tal Shiar live on, since operatives were routinely placed on colonies. With Romulans now scattered and evacuated to other planets, the Tal Shiar will undoubtedly be working overtime in order to rebuild the prominence of their race and this is where they could come into play during Star Trek: Picard. Firstly, the group are unlikely to take a kind view of Picard harboring two former who broke their stringent rules, immediately putting the former captain at odds with the Romulan intelligence service. However, the Tal Shiar might also be responsible for the Borg prison glimpsed in the Star Trek: Picard trailer. The Star Trek: Countdown comics already highlighted how the Tal Shiar were dabbling in Borg tech, so it perhaps wouldn't be too surprising if they were now capturing the cyborgs also.
As for what might bring Picard and the Romulans together in Patrick Stewart's series, it might also be possible that the Tal Shiar are the ones pursuing the girl Picard is trying to help. The trailer shows Dahj in combat with some shady, masked types and, given the already strong Romulan presence in the series, the Tal Shiar could be a safe bet as the arch antagonists of Star Trek: Picard, with a grudge to bear against the title character after the destruction of their homeworld. No doubt they will be even more dangerous without any established government to serve.
Star Trek: Picard premieres January 23rd on CBS All Access.