I know, I know, it's to the 1 to 3 people on the panel who are there to perhaps hire you or award you money, but that's not what I mean.
I mean, in the specific aria who are you singing to?
Depending on the aria, it could be yourself, your lover, your sibling, the crowd (onstage), the crowd (in the audience), or some combination of the above.
The point is to remember where your character's is when you are auditioning - it will make it feel more like the performance you want it to be, and less like a gymnastics competition, which you definitely don't want it to be!!