Envy and jealousy. This is the importance of the Mindfulness practice - because if we continually push away any negative emotions, then we are not getting to the true cause of them, and therefore it is difficult to let go of them. We have to open to the Dukkha so that we can see the true cause of our Dukkha, and the results of this attachment in ourselves. It is the key towards having Compassion for oneself. So when envy or jealousy is present, we try to use mindfulness, otherwise we may push it away and this aversion will only cause it to arise again, because we haven't gotten to the true causes that create it.
After we have noted it, we try to see how it feels in our body, that it's suffering. The feeling of lack, which is very unpleasant and as far as changing the view that creates it, it is developing the capacity to feel joy - Sympathetic Joy - with ourselves and others. Which is often much more difficult than developing compassion.
Why should that be? After all, most of us would like to have more joy in our life. However, it is much easier to open to other people's suffering, because we don't feel threatened by them. But other people who have benefits that we would like, can be very threatening to the ego. So a certain amount of capacity to open to our good qualities, acknowledge them - rather than just developing a sense of a negative self, learning how to reflect on them, take joy with them, helps us open to the goodness in others and the benefits that others have.