Have you looked at imcrop()? Imcrop has an interactive mode and will output the selected RECT parameter when the appropriate syntax is used.
[cropped1 rect] = imcrop(thispict);
You can then call imcrop using that parameter
[cropped2] = imcrop(thatpict,rect);
To display the images, you could do that any number of ways.
You could use subplots or tiledlayout
subplot(1,2,1); imshow(cropped1)
subplot(1,2,2); imshow(cropped2)
or you could use montage:
montage({cropped1,cropped2})
or since they're the same size, you can just concatenate them and show them as one
imshow(cat(2,cropped1,cropped2))
