gigaflopThat's not a very good representation of scale... and it's at a poor angle. Why not something more "everyday", like a ruler or a pen? or even like, a chapstick tube. Anything, really. how about a regular sized d6?
redsevnAgreed, on top of that, there are many profiles for mechanical keycaps. Even keycaps of the same profile and manufacturer can vary depending on the row.