Sure! The standard path is \config\images
Inside that path goes the boxarts that look like the following (I'll use SSBB as an example):
View attachment 387432
The naming structure for all artworks is <titleid>.png, so for Brawl it would be RSBE01.png in my case here.
There are also three subdirectories which have different types of images.
View attachment 387433
2D contains images such as this:
View attachment 387434
disc contains images like this:
View attachment 387435
full contains images like this:
View attachment 387436
Edit: just realized you said this is a WiiWare title and now I'm not sure what you're looking for since WiiWare games don't actually have box arts. Maybe it'll work the same way still.