I suspect that the higher metallicity of that star may indicate that the star is significantly younger than the Sun. Either that or some nearby supernovae popped off before the star was formed, since the supernovae and late stage large stars are the source of most metals.
Note: In stellar chemistry, anything bigger than helium is a “metal”.
Yep. Our sun is only 4.5 billion years old, so there as been plenty of time for prior generations to have been born, lived, and died, and bigger stars burn faster to boot. How much 'metal' went into any given star should be highly variable. Back of the napkin calculations (based on the very thin data we have about the other star and our sun) suggest that a star like ours but with .3% trace elements would have a cycle of 5.3 years, .4% a cycle of 3.8 years, and so on. This might be the source of variability in Cepheids (a type of star that varies its output cyclically, with periods as short as a few days). They'd have to have trace elements on the order of .8%, and that's leaving out other factors like size and age, where they tend to differ substantially from our own sun. All speculative, however.