Not at all.....Swelling calyx's are standard...which is what you have, a normal swollen bud ...and looks decent to...
Foxtailing is when the Calyx's Stack and keep growing which allot will say can be from genetic traits, heat, etc.....IME Its mainly a response to excess N mainly in sativa varieties...
But it would look much diff then what your showing...
This is Foxtailing where it will look stacked or even braided...hope that helps....power to it
FOE20