This was quite the difficult connection for the fandom to get! This picture was seen at Birmingham 1, Birmingham 3, and Newcastle 3. There was no clue who it was until after the second time we saw the pic. Turns out, nope. Two weeks later the picture was used again, and this time we finally got it!
There were a few different people floating around as possibilities, but none were a great match, and nobody could find the exact picture that was in the frame. Based off of an anon suggestion, supportingharrystyles contacted that person to confirm. Wrong person, but they put up a post on Facebook to try to figure it out. Crowd-sourcing is amazing, because several people suggested Stella, and after being tagged in the conversation, Steve confirmed it.
The specific image used is of a flyer for an event that took place on October 19th (we were shown the photo before the event took place, but the connection wasn’t made until after the event). Also included in the event were other former BGT and TXF contestants. Most notably, Stacey Solomon, who was sued by Modest for breach of contract, went to Max Clifford, and has spoken about how her contract from TXF trapped her. For a more detailed explanation, see this post.