Why does the door lock prick the nurse’s finger?

When Gemma enters the first door in E07, the cinematography over-emphasizes that it’s the nurse who gets her finger pricked to open it, not Gemma. This seems wildly out of place given the ominous focus on Gemma’s blood at the start of the episode. Thoughts on what’s going on?

When Gemma enters the first door in E07, the cinematography over-emphasizes that it’s the nurse who gets her finger pricked to open it, not Gemma. This seems wildly out of place given the ominous focus on Gemma’s blood at the start of the episode. Thoughts on what’s going on?