That top clicky box is going to make more sense if you have multiple places to crosspost to. The top clicky box is "crosspost, yes/no?" and the bottom one is "and do you want it here?", which is silly if you have one account to crosspost to, and less silly if you have more than one and you don't necessarily want it going to both. So you could do "crosspost, yes, but only to LJ and not IJ", say.