It is the intended behavior that you are prompted to enter the information when clicking the "Snapshot" button on the HUD. By clicking the snapshot button, you're telling the HUD that you want to add an item.
If you don't enter any data, the prompt will disappear after one minute, and the HUD will go back to normal mode.
If it doesn't, reset the HUD scripts (edit the HUD, and then, in the "Content" tab of the edit window, click "Reset Scripts"), or get a fresh package at the redelivery station in the inworld store.
You won't lose any data if you get a new HUD.