Like the simple straight forward approach!
Wish: Implement a gapless mode for images with different aspect ratios.
e.g. Irfanview puts the pictures together side by side without a gap (and only in this way)
Could be done as an additional "rearrangement".
Sorry, forgot the way to handle different aspect ratios:
1. if height differs, scale to same height for arrangement "all in single row" -> results in wider or narrower appearance for treated picture
2. if width differs, scale to same width for arrangement "all in single column" -> results in higher or lower appearance for treated picture