We only submitted 5 photos that were taken before our marriage, and from the time I met with my wife to our wedding, it was about a year. The way that I wrote my letter was like to pill off onion skins, layer by layer to demonstrate how our relationship evolved, I actually used the words like "we hangout just like friend (without any benefits)", "then after 6 months into our relationship, I was no longer required to sleep on her couch." And at the core of the onion, you detail your feelings about why you think this man/women is the one that you like to commit with, one of my paragraph was like "
To be sincere and to open up yourself to accept someone into your life is always the most difficult part in a relationship. Fortunately, we did it. From the very beginning, we tried not to hide anything about ourselves from each other. We talked about our life experiences, our own marriage failures, our expectations in this relationship, our families, and etc., we shared good times and bad times together, laughed together, being sad together and being silly together, the comfort zone we built up around us, allowed us to expose our true selves to each other without any hesitation. And that was particularly important to me, because the trust, the safe harbor and the caring that my wife built up for me, really helped me to reinstall my self esteem, and literally speaking, it was my wife that turned my life around and put my life back on track again. For that, I shall be grateful forever to my wife."
You gotta present a picture to the person who review your supporting documents, nobody really cares things like how many times you said I love you to your spouse, you have to use the words to lead the VO into your relationship, use your true feelings to convince the VO that your relationship is genuine at every stage of your relationship. By writing like "Yesterday we spend whole day together to celebrate my birthday, last month I flied to see my husband" isn't powerful enough, and if you repeat the same thing dozen times, it just is rather annoying. Photos can be staged, expenses can be pre-setup, but a strong personal feeling that based on other evidences cannot be faked in most cases.