Redrawing a content of a subplot in programmatic gui using dedicated control in another subplot

• I am a novice in Matlab so this is a variation of a question asked in https://www.mathworks.com/matlabcentral/answers/311692-how-to-get-the-handles-of-a-subplot which I could not get running. To identify the problem, I drafted an example related to the management of handles and the use of callbacks to update subplots. The real case is a bit more complicated, but this one gives the idea.
• The case is simple: we have three subplots. Top [1] and Bottom [3] subplots are populated with images and a panel with 3 buttons is located in the third spanning subplot [2,4]. The first and the third buttons should rotate the image in top and bottom subplots respectively and the third resets the image to restart the process.
• Buttons partially work - they activate the actions in the target subplots
• Pressing the buttons to redraw the panels after the rotation fails - why? any advice? thanks for your comments.

Answer 1

[AlexanderM]

Update. The problem is solved using global to store the state of the image. It is not elegant but perhaps acceptable. Please share with me a solution that does not use global.