If GB keeps tagging Jack people are going to start realising she's there and questioning her motives and integrity.
She has done absolutely zero by way of promoting this, which is sort of the point of SM and activism.
She's taken the gig because it's her only opportunity to jump on the publicity bandwagon and for the fee. If she genuinely wanted to end foodbanks/poverty then it would be a constant flood of SM posts and retweets. Everyone else 'at conference ' has been taking selfies, tagging themselves, tagging MPs etc
It's almost like she's frightened of being caught there.