Use fencing.

The solution I am looking for is for summertime--some plant material to focus the eye on that will distract from the rather bare trunk of the juniper.

You'll likely know by the end of the summer just what is going to regenerate. I have a juniper hedge outside my den windows, and the winter before last, deer did a real number on it. This last winter, it was left pretty alone because I put some black plastic bird netting on it which the deer do find annoying. There's been very good regeneration. So I'm just leaving the netting year 'round and the junipers can grow through it. You can't see it unless you're on top of it.

One of the grasses with a nice plume is about the only thing I can think of that would give you enough height to hide it, meantime.

This is interesting. I didn't know deer liked juniper.
Two things that I know of that may work instaed of fence that other people have had success with are:
1. Hang bars of Dial soap from a string about 6 inches off the ground in the area you want the deer to avoid. Deer hate the smell of soap.
2. Mix 1 beaten egg with 1 quart of water and spray it on your junipers. Eggs are repulsive to deer.

You may also try posting this question on the Nature Forum with the subject on how to repel deer.

Here is a link that might be useful: How to Repel Deer

if hungry enough deer will eat anything that doesn't kill them.

so...are you planting this screen on yhe north side of a sun loving plant? because if it will regrow...you don't want to shade out the new growth.

deer have remarkably sensitive browsing abilities. often they only eat the foliage and leave the bark and more importantly the buds intact. you'll know soon.