There are decorations, but it's mainly about the ice skating.
One thing I hadn't realized before is that the location - Jerry Willey Plaza - seems to fall under the Parks and Recreation department. There are frequent repeating events, and some good information available. It may also be the park most conveniently located in relation to the MAX lines.
City bureaucracy may be the reason that waivers are required, though that seems like a good idea anyway. Also, some helpful notices.
While there were more supplementary activities before Christmas - like musical performances and vendor booths - there are still special theme nights coming, and the nearby businesses include a Thai restaurant, coffee shop, French bakery, and gelateria.
I suppose the primary pull is outdoor skating, and possibly convenience of location, given that there are fewer ice rinks now and the remaining rinks have gotten smaller.
Bright orange rental skates help with uniform safety.
There are 90 minute skating sessions interspersed with 30 minute ice clearing sessions that leave a fresh ring of "snow" outside the rink, which is very tempting for snowballs for the children hanging around. Well, without heading into the mountains, it is the only Christmas snow around right now.
Most people just seemed very happy to be able to strap on their skates and glide.
https://www.hillsboro-oregon.gov/departments/parks-recreation/recreation-fun-/special-events-/winter-village