These maps visualize the level of funds being paid into the EU budget, and those being payed back by the EU budget.
The colours symbolize the economic prosperity of each member state (the warmer the colour the less prosperous the state).
The size of the states symbolizes the amount of funds being paid in, or taken back.
The maps have been created by Benjamin Hennig towards his Worldmapper initiative, for which he creates gridded cartograms in order to visualize economic, political and social similarities and differences in Europe and the World.
According to the author, specifically these two maps reveal that:
"...beyond the net benefits and contributions, large proportions of the money are actually redistributed between the wealthiest member states...
Although the poorer countries such as those in the east of the EU indicate a certain element of solidarity in the redistribution, a lot of the money goes back to the largest contributors. "