Disclaimer: Naruto isn't mine
Being a dad means taking a picture that causes her to scream every time she sees it.
It was a harmless joke. Iruka didn't want to see what he looked like during labor and the C-section. He asked for no pictures and no cameras. Kakashi vowed to keep up with that promise. But the temptation! Damn it the temptation! The wonderful, sweet, evil temptation of just taking one harmless photo of what Iruka looked like during the pregnancy! That was all. That was it. And it wasn't like Anko wasn't going to take one anyway. Kakashi was just helping to speed up the progress.
That is the extremely good reason of why Kakashi brought in a camera to the delivery room. It was the best excuse he ever came up with. It deserved to go into The Excuse Hall of Fame. And childbirth was a miracle of life, it would make perfect sense for him to want to capture a moment of it. All in all, a very smart decision made by Kakashi.
And the look on Iruka's face when he saw the picture of him trying to see over the screen to get a look at the baby, was priceless.