So is it possible to make this work
#element img:hover #otherelement {...}
like
#element:hover #otherelement {...}
What your first selector is looking for is something called #otherelement inside an image. Images can't have child elements.
#otherelement
If the element is a sibling of the image, you might want to try img:hover~#otherelement or img:hover+#otherelement.
img:hover~#otherelement
img:hover+#otherelement