It makes a difference because of the direction the camera is looking versus the facing direction of the sprite. Generally Z positive is considered forward, so Look At is changing X and Y to aim Z positive directly at the target object. This has weird effects if you're looking along the wrong axis with the camera and the character world space is not assuming Z is forward. Move towards wouldn't be affected because its simply translating between two positions and doesn't care about which way is forward, thats why you need to have something not only move toward an object, but also look at it to appear as it is actually going forward.
However, I don't do any 2D work and the new 2D Unity features are foreign to me so I don't have any practical feedback on how those actions work with 2D shapes. Technically they all should work but their actual behaviors are going to be different if you have a case where Z isn't the sprites look direction. You can always manually figure the angles out with other actions if that is indeed the problem.
