Me 2 months ago on why Glass should add a like button:

Maybe this is a terrible idea and I'm in the minority here, but I really do think that I would enjoy the app more if I was able to give lower-friction reactions to people's photos. I still like Glass quite a bit, and I browse it everyday, but I do often feel like I don't have the energy to comment on all the photos I like, and that's a shame.

And:

If they don't want to show like counts, I get that, but treat them like followers: show me a notification when someone likes a photo, but don't show me a total likes I've received. At least then I might see more of an indication that people liked what I posted and that I'm not posting into the void.

Glass today:

With today’s update, you can now Appreciate photos and comments on Glass! Always private and no counts, we wanted to make sure it would never drive competition.

Long story short, they added exactly what I wanted and I’m super happy they did!