But when I have the same coding with a column page it will not enlarge, the issue appears to be caused by the column structure, but I can not see how to resolve it.
I don’t think its a good idea to resize that image from the middle of a column anyway as that looks very odd.
The reason the image is not growing is because you have a max-width:100% on all images so it can’t grow bigger than its container anyway. You would need to set max-width:none on the thumbnail to allow it to grow but the effect will be bad especially as you are not absolutely placing the image somewhere.
If you want this type of effect then a lightbox script would be a better choice and there are many to choose from.
As Ron said make sure you first have valid code as a good base to work from
Another css alternative would be to scale the image via transform as this behaves differently to actually altering its dimensions. Rather like relative positioning, it will not alter the element’s original space within the document flow or be bound by the space of its parent container.
Using something like transform: scale(1.2); would expand the image without pushing surrounding elements away or constraining the image to its parent’s size.
You can also adjust the transform origin to best effect.