I discussed my previous experience and exposure to mental health issues both in my family and at previous jobs where I worked as a care worker. We also discussed my competencies and hypothetical situations and my response to them.
I dropped a 2L bottle of milk and the milk went everywhere. Staff in the chilled department were not long cleaning it up, causing no fuss at all. Only for this, it would have been extremely embarassing. Thanks to great staff they saved this.