As if to confirm this

Does "this" refer to "it must be above board" or "Is this supposed to be happening"?

Context:

Before there’s time to contemplate that question, another figure pops up near the entrance of the museum. A young woman this time whose rhythm is more measured: a smooth, considered action that gives her plenty of time to anticipate any obstacles. Serene face, elegant. Used to running distances perhaps. There aren’t too many visitors about today but, like me, they’ve all stopped in their tracks, a look of slight puzzlement on their faces. Is this supposed to be happening? Two gallery attendants at either end of the galleries calmly monitor the situation, ambling up and down, keeping an eye out for potential blockages. So, it must be above board. As if to confirm this another runner emerges. This one’s going hell for leather, his straining face tilted to one side, as if being pulled by an invisible force attracted specifically to his right shoulder. Much huffing and puffing. People smiling now.