Orb Mosaic

Despite all of my good intentions I've been back on photoshop - this time looking at John Gravett's youtube.  The Orb mosaic shown here is 24 pictures from a sailing holiday I did last year.  The extra is 9 pictures taken on January 31st this year - Brexit gatherings in London (I know some people may react against Brexit, but just take the mosaic for what it is).
The tutorial by John is very well presented, but there are some things that need thinking about if you use a Mac.