The last time I evaluated these for use in my app, I found that the "consistent" and "minimalist" visual style makes it really difficult to recognise object/plant/food emoji from one another by shape or at a distance. Other emoji have clear shapes, but not enough internal detail to understand what they mean. this is especially problematic with a set of non-Android, non-Twitter, non-Apple emoji, where users haven't learned the shapes yet, but have to go by looks. It looks like the creators of this project wanted "function over form", or at least "form follows function", but in their pursuit of Bauhaus they accidentally ended up with Droodles.
Even the person ones aren't great. I actually thought that the baby was a hunchbacked old man. And the facepalm looks like someone covering up one eye to read an eye chart. I seriously wouldn't have gotten either of those without the caption telling me.
