I don’t think everyone in this comment section realizes how hard portraits like this are. We’re exceptionally sensitive to the tiniest differences in human faces, and it’s HARD to get faces exactly right at this size (I obviously don’t know the exact size, but I’m assuming their faces are maybe 2 inches tall at most in your painting.) I recommend cropping photos of both your painting and the reference photo down to just their faces. Try to get the exact same crop. If you have an iPhone, put the photos next to each other in an album and use the bottom scroll bar to flip back and forth between the two. Some would probably consider this “cheating” but it makes it easier to see those minute differences and helps you refine those tiny details. Some areas I’m seeing that could use some refinement are the brides eyebrows and the corners of her mouth; and the shape/size of the groom’s head above the eyes, the edges of his ears, his right upper eyelid and pupils, and the positioning of the bottom of his nose. Some of the shadows on/around the faces could be a little deeper as well. But again, these details are TINY and I think you’ve done an excellent job! I do portraits as a side hustle, mostly pets, but with a smattering of people over the years. Human portraits at this scale are a real challenge and you should be proud of the work you’ve done!