The Mendenhall Glacier is visible from the visitor center parking lot. But it's still pretty far and if you traveled all the way to Juneau, Alaska, you probably want to get up close to the blue tinted ice.
Touching the face of the glacier can be tricky. You're separated by cold, silty water, and a hike over the ridge could take hours.
Visitor center staff know that. And inside, they use it to prove a point.