They're both pretty heifers. The first one appears to be more complete & fault free, particularly on that hind leg. I like the length of body in the second heifer; she seems to have some extra set to her hock, and that may just be how she's standing in the picture. The first heifer balances up better to me and appears to have more shape to her forerib and more depth to her flank.
Thanks for posting, and good luck with the heifers!