It's the day of the wedding, the groom is standing up front with the pastor awaiting the arrival of the bride. The first time the bride and groom lay their eyes on each other it should be just magical. The second they see each other they have tremendous amounts of love in their eyes. And that what you want to be captured. Some people would rather do them before the wedding in a more private area so that they are not rushed, but the more traditional people would prefer to do it the more traditional and old-fashioned way.
So people may argue that it would be a better idea to stage the first look and do all the wedding pictures before the wedding so that it looks all nice and no one looks stressed or is sweating buckets, but the more traditional people believe that it should not be staged and that the pictures should be raw, emotional, and in the moment. The first look is the second the groom lays his eyes on his bride and should be something that he'll never forget and getting a videographer and wedding photographer is the perfect way to make sure that you never miss a single moment.
Would you rather have the pictures natural and in the moment or staged and hours before your actual wedding? That is just something to think of when you are planning your wedding. Lots of people have different opinions on whether they want a traditional wedding or a nontraditional wedding. Nowadays not everything is gonna be traditional in a traditional wedding and that's fine, but things a white dress, a wedding party, waiting to have the first look the second you walk down the aisle, etc. Some people agree that doing the First Look before the wedding makes it easier to get pictures in and helps them resolve some nerves but others argue it's not as romantic as seeing each other at the moment.