iCloud accounts and account images

My wife and I share 1 iCloud account so that our calendars, contacts, keychain, and calendars are the same on all our devices. This is so that there is no confusion/errors/missing items on these applications on both her and my phones. I set up an image for this iCloud account that is a standard emoji unique for that account. Every time I open MY card in Contacts I find that the system substitutes that standard emoji for my photo. If I change it back then the "common" iCloud account's emoji changes to the one that I just changed on MY contact card. I don't associate a phone # with the common account, just the email address and neither my wife nor I use that email address for our mail or iMessage. I have tried everything I can think of to stop this but so far no luck. Does anyone have any suggestion beyond just doing away with a common place to synch appointments, contacts, etc. across all our devices?