The Hagala walk or Hagala step could simply be defined as walking with the 3/4 shimmy. The 3/4 shimmy is what we Arabs call the Moroccan shimmy. When you add a hip twist with the lift, it becomes what we call the Algerian shimmy. So technically the Hagala walk is walking with the Algerian shimmy as we have to twist the hip forward to walk with a 3/4 shimmy.
Check out the videos for the Algerian and Moroccan 3/4 shimmies here for details.
How to do the 3/4 Moroccan shimmy
How to do the Algerian 3/4 shimmy