Hi,
I have a shadowbox around the widgets using CSS. Is the same possible for images or is that not advisable?
Its definitely possible. but as for it being advisable? It depends on many things. There are definitely things to consider.
If your site follows a specific branding guideline, consider consulting with the designer if adding box shadow effect is applicable.
If you’re just winging things and is going by feel, then its really up to you.
Personally, I think adding box shadow is fine as long as its subtle. I find it useful when I want to put emphasis on a particular section/element as it can be used to make things stand-out over certain backgrounds or group of contents. 🙂