I believe this has something to do with the default figure position setting of your teacher's computer.
If you want to increase the figure size, you can add such scripts to line 55 and 56.
fig = gcf;
fig.Position(3:4) = [200, 150]; % 200 and 150 can be replaced with the width and height you want.
This will change the figure size as shown below.
If you want to change the default figure position setting in your MATLAB, consider using such scripts.
set(groot, 'DefaultFigurePosition', [x,y,width,height])
% To reset:
% set(groot, 'DefaultFigurePosition', 'factory')
Lastly, you can open the figure in a new window and enlarge it.
