they wouldn't have known from the photos, you could have been applying for a unmarried partner visa, a fiancee or spouse visa.
they should have known from your letter of support, they must have looked at your evidence because they refused you a 'unmarried partner visa' because you didn't submit any evidence that you lived together for 2yrs, how would they know that unless they looked at your evidence.and if they did look at your evidence they should have realized from your evidence that you wanted to apply for a fiancee visa.
ask your b/f to contact his MP, maybe they will do something..