This is the second, third in total, topic of request for enhancement to our beloved 'create strip of images' module.
Right, look at this below screenshot of VLC's main preferences window;

Notice the little picture diagrams which gives a small and 'smart preview' to the user of what the window would look like if it was changed to either choice.
Something similar to this could be considered for 'create strip of images' window but perhaps as a much more smaller picture that enlarges as a preview upon hold-clicking on it (think of XYplorer's 'blow-up' preview pane). The 'smart preview' pictures would ONLY use per-defined example pictures and not an actual preview of what a user is about to create.
A preview would be needed for 'horizontal alignment' 'vertical alignment' and 'mosaic' plus 'jagged mosaic'(if that feature get's approved)
In fact, a dynamically fade-in/fade-out 'smart preview' picture could go in the area highlighted on the window (see below image);

a 'smart preview' picture would dynamically evolve as user makes each setting before going ahead with the 'Create' action.