Showreels have changed a lot in recent years. Whereas a few years ago it was mainly montages (scenes cut together) that were presented in a file, the focus is now increasingly on individual scenes.
The advantage of individual scenes is that they are well labeled and provide a better overview without having to waste time clicking through a file that is several minutes long.
You can see immediately whether it is a dramatic scene, for example, and under which direction. In addition, individual scenes can be exchanged more quickly without having to recut them.
In addition, most portals allow you to link the individual scenes to the skills and credits.
Individual scenes should not be longer than 3 minutes. Ideally, they should begin directly with the actor's acting and speaking scene.
It should be noted that showreel scenes are not necessarily for entertainment purposes, but should present the actor in the scene.
For a quick overview, it sometimes makes sense to use a short compilation with best off scenes (Trailer for actors). However, these best off scenes should only contain short excerpts of 10 to 20 seconds and the trailer should not be longer than 3 minutes.