Casting HES on another person shows the messaging for me instead. In other words,

You gesture at Leilond.
You contribute your harnessed streams to increase the pattern's potential.
A glistening net of coiling tendrils interlaces itself across his muscles, outlining each vein and contour with sparkles of white light.
Your body feels noticeably stronger.

It works properly in that the spell is actually going on him, but he also didn't receive any messaging about being stronger.