That’s what I thought as well, the wedding in itself is the entertainment of the night. But some posters have raised the point that they expect to be entertained/entertain their guests at the event.
I think it’s a lovely idea to keep the slideshow playing in the background, even if it has to be on repeat. But from what I’ve seen personally it’s something that you have to pay attention to. It’s the 10 minutes of entertainment, and then moving on to something else.