Back at Special Forces HQ, Sonya is threatening to kill D'Vorah if Kotal moves, he gets upset and prepares to attack. Raiden comes in and zaps the shit out of everyone. Kotal is pissed and says "Earthrealm. Our fate will be yours." Kotal and his comrades prepare to leave, Kotal opens some kind of portal. Raiden says to him "You promised me you wouldn't use that portal stone anymore, Kotal." Kotal replies with "And after the netherrealm war, you promised our worlds would cooperate." Raiden informs Sonya that he's looking for her daughter.
Now back to the match, Frost is beating Cassie until she gets the upperhand and knocks her out. She's told to finish her and refuses, until they put Jacqui at gunpoint. Right before she kills her, the place is attacked by the Black Dragon's Jarek and Tasia(From MK: Special Forces). Jacqui uses the distraction to get the keys to the cage, and frees Cassie. They take Frost to safety to make up for almost killing her. Jarek and Tasia confront them, they request Cassie's presence. They start running, and I believe what Cassie's doing is filming whats behind her on her cellphone so whoever finds it will know who took them. A portal opens and sucks them in, based on Jarek's dialogue I believe it is theirs. She drops the phone.
Sonya is scrolling through the phone and sees multiple "Daddy Cage" calls in Recent Calls. Then it shows a picture of Erron Black on her phone, not sure what this means. Sonya is getting Johnny and going to outworld. "Kotal Kahn is a dead man".
So I'm thinking the picture of Erron is from when she was filming behind herself and Kotal possibly sent the Black Dragon and Erron there to kidnap Sonya's daughter after she refused to cooperate with him.
Edit: Actually, more likely it means Erron was inside the portal and that's what was caught on her phone.