As a reptile handler, twice a week is far too often. Once a week, even as a baby, it's enough. As a snake grow larger their metabolism starts slowing down. A ball python, for instance, will eat once a week as a baby and then as little as once every three weeks as an adult.
DO NOT feed a snake just because it looks hungry. They are opportunistic feeders and will easily become obese, developing liver and heart problems.
Furthermore, the enclosure depicted is far too small. A rule of thumb is two adjacent walls should equal the length of the snake. More clutter for non desert species to allow the snake to feel less exposed would also be good.