 In one scene, The Three Stooges (qv) are sitting in front of a  lion. If looked at closely, it can be noticed that there is a glare  behind them. There was a sheet of glass put up between them and the  lion for the scenes shooting. Even though the lion was old, docile,  and tame, Shemp Howard (qv) panicked and refused to do the scene.  As a result, the glass was put up to separate them from the lion.