Anni wondered what they do all day. In a word, they rest. Most of the "mob" will be females, and all the mature ones will all be pregnant, or carrying a "Joey", or have a "Joey" at foot, as in the second photo. Some may be in all three stages of motherhood at once.
The other thing about such a "mob" of Kangaroos is that they feed in the early evening and early morning, when the grass is most likely to have some dew on it, allowing them to drink and feed at the same time. During the day, the "mob" usually rest under a stand of trees, where they can get some shelter from the sun.
Zoe was quite pleased to get a photo of the male taking his weight on his tail, just about to propel himself across the ground at ultra-slow speed, using the tail as a "prop" while sliding his huge back feet forward.
CSIRO biologists have studied the amazing fertility of Kangaroos, and one fact they have discovered is that the female (a "doe") can simultaneously produce milk at different stages (from different teats) to suit the developmental needs of an "independent" Joey, like this one, and a smaller one which is almost certainly a permament resident of the pouch.