VOs never asks voluntarily proof from us. its us who are sending voluntarily proof for the sake of our own satisfaction. People who are doing fake marriages, knows all these tactics so these fake people can talk day and night, on chat video calls, love notes, love letters etc and then send it to VO to show that their marriage is genuine and let VO reads their love notes...lolz.. but if a marriage is genuine then at least Sponsor can visit their spouse at least after 3-4 months and then take pictures and believe me these pictures can be fake and just pose for the sake of showing genuine marriage but at least visiting spouse in back home cost money, travel, hoteling shopping dinner so at least VO can think something positive.
But not visiting your spouse and just sending love notes on whatsapp, skype i don't think so going to make any difference.
my 5 cents thoughts