The desktop shows the full website , in this display you can easily see four columns with the whole menu bar at the top of the screen, and the text is easily seen so their is no need to zoom in or out to see the whole paragraph.
In the Apple website the image is set to still be centred and up close in every form of device, the layout of the grid moves to one column when being seen on Mobile, the text is seen to be bigger than it is in the desktop version, the menu is activated at the top left corner instead of the menu being over the top of the screen so theirs no need to scroll from left to right.
In the tablet design the grids used in the layout goes from six columns to three columns, the menu changes from the top left side which it is on a desktop to only having 3 of the titles at the top of the screen ,the images get slightly bigger but because in it only has three columns the grid has turned into two rows in each section of the site.
The grid in this website because one column per section for the mobile, the menu bar has turned into a different button for mobile phone which i think works better because i think it would be easier to find exactly for your looking for, the main headings for each things slightly smaller. whereas in the desktop each part is sectioned off in columns of three
The tesco website does not work as when you see it on different platforms it does not resize into grids and you are having to scroll left and right in mobile or tablet form , this only really works as a desktop.