The arrow shows the saving to be had when the file is GZIPped.
I have searched all over the place for an explanation of why not all of the files have been GZIPped without finding a satisfactory answer. Maybe someone here can throw light on the subject.
Seems the code has to move up a bit, moving it up above the other app.use code will make it work for static content. Will have it updated with the next Wappler update.