Standing this way, you should take notice that you now have the most ballistic protection available from your body armor. Another selling point is that because the stance is patterned after the way you walk, it's more comfortable and readies you for what comes next. No one walks at a 45-degree angle. Any SWAT operative will tell you that smooth is fast; this applies to stance work as well. The fewer adjustments or changes you have to make to get into your fighting or shooting platforms, the smoother you will become.
Transitioning from the interview stance into your fighting stance is a simple task. You merely bring your hands farther up, open with palms out, making sure your fingertips are under eye level (which ensures that your vision is not obscured). You establish a lead and back hand like any other fighting stance, which allows you to set up zones for each arm.
I don't recommend closing your fists unless you need to. Once you close your fists you limit your tactical options by losing your ability to parry and grab. Also, if phone videos are recording and you have an open hand stance, it looks like you have taken a defensive posture vs. an aggressive one. The real issue is that if you make your hands into fists prematurely, you tend to tense your muscles in the arms and shoulder areas, expending valuable energy that you might need later.
As your lead hand is positioned forward and your gun hand is back, both of your elbows are resting close to your side. In that position, you can train yourself to cover your sidearm with your gun-side elbow. This creates a form of gun retention and allows you to feel if someone is grabbing for your weapon.
Transitioning to your shooting stance is simple. Draw your sidearm and assume an isosceles shooting stance, making sure you bend at the waist, roll the shoulders forward, and lock out your elbows. Because your feet and hip placement has stayed the same during your transition, you are ready to move in any direction in a tactical manner without having to adjust your stance first. By keeping the same base, the transition from interview to fighting to shooting and anything in between has been made much more efficient.