The keycaps themselves are slimline too, more in keeping with what you'd find on a laptop. Keychron achieved this by developing its own mechanical switches that are slightly more compact than traditional switches. The important thing though is that it's mechanical, slim and wireless.
You can choose to have a number pad, or not, or choose to have Apple keys or Windows buttons. For those with Macs, or those who want a slim wireless option, the choices are limited. For the most part, the mechanical keyboard market is filled with big, chunky keyboards and generally only really available with Windows keys on them.