Move the mouse from left to right across the stage area. As long as the mouse is touching the picture it should stay doubled in size. However, when run under Scratch 3, the sprite stops sensing the mouse when the mouse is outside of the area defined by the sprite's 100% size. This problem is One of the issues mentioned in this post, which uses drawings instead of a picture, where the sprite should be resized when touching the mouse. : https://scratch.mit.edu/discuss/topic/308114/?page=13#post-3282365
Scratch 3.0 link : https://beta.scratch.mit.edu/#253064159 Compatibility mode: https://beta.scratch.mit.edu/compatibility-testing.html#253064159