Set sprite as mirrored in Layout view?

I want to place several enemies on my layout using the Layout view in the C3 editor, some of which are facing right (normal) or left (mirrored). Is there a way to do set the Mirrored property using the Layout editor? I see a setting for 'angle', but setting it to 180 rotates the sprite upside down.

If not, my thought is to set an instance variable called mirroredAtStartup, and programmatically mirror the sprite on layout start based on that value. Or is there a better solution?

Not sure why you would ever need that in layout view. Yes you would use a Set Mirrored action. If you're talking about instances of an object here then yes a variable sounds fine to pick between mirrored and not mirrored.

Set a negative size in the Layout View. 'Set mirrored' is a shortcut for 'make width negative'.