The big difference is the build of the heifer. I agree that for a lot of judges these days it seems that they wont their heifers to look awfully terminal, and a market heifer should have that appearance. A breeding heifer should be very refined and feminine, while a market heifer is going to have a more terminal or steery appearance. Yes a lot of freemartins get shown as market heifers because the lack of hormone production typically makes them mature a little quicker and makes them more terminal in their appearance, but a lot of people will choose to show any heifer that looks terminal in the market shows because typically she should get hit pretty hard in the breeding shows for being terminal appearing.