There's no way of telling whether this photo was taken just before this couple got married, or just after this couple got married. We're also unsure which would be worse. Why, on your wedding day, would you find it necessary to head to Walmart to stock up on essentials? Couldn't you have sent someone else - for example, one of the guests who'd come to your wedding?
There aren't many reasons why this might have happened, but let's speculate that the wedding reception has run out of food, and so they've come to stock up on the buffet. That would be a kind and noble thing to do, but it's still a duty that should be attended to by the groomsman or the maid of honor. Also, is it us, or do they look like they've had a beach wedding? Just how far have they traveled to arrive at this store? Did they elope?