Turn an image into a mosaic made of emojis.
Figure out the average color value of each Emoji?
What is the source for the Emoji character? Using the actual system character seems exceedingly hard — I don't think I got node-canvas installed correctly, and even so I don't believe it would render the Apple Emoji system font.
Get a package to read pngs and make a lookup table?
Use a prebaked lookup table like in emojicam?
How to layout the emoji?
The Emoji should be tightly packed, laid on top of each other, and skewed angle to give it an organic vibe. To get an organic layout (rather than a grid layout) Poisson-Disc sampling is cool, here's a great example.