Isnt this advertising God? When they post those pics on Facebook?

[david w]

It's arguably sinful hypocrisy. Jesus spends a lot of time in the New Testament (don't know about the Book of Mormon) warning against public displays of faith unless there's a real point to them, because flaunting your piety to win the esteem of men is sinful, and will not be rewarded in heaven. Unless you have a good reason for displaying your faith, better not to do it, and avoid inviting temptation.

Note that there's nothing inherently disrespectful about advertising religion. That's commonly known as evangelism or proselytisation. It's how and why you do it that matters.