Weird bars and more have been noted before. http://forums.androidcentral.com/htc-one-m8/382408-weird-icon-status-bar-when-sending-text.html

In short, SMS text messaging has been changing over time to the point that I'm seeing a lot of bars, indicators and even the weather show up in the message app.

What's common to all of them is NO DOCUMENTATION. Long ago we could open the product manual. Then it was a file or doc on the system. Today they don't bother writing it at all.