Part 1
As income per person rises,  the percent of labor force in agriculture falls. Income per person is the average amount of money each person makes. The Agriculture sector is the percent of people working in the primary sector doing things like farming. As GNI rises, percent of people working in service sector rises. GNI is gross national income which is all money earned plus foreign investment minus foreign debt. The service sector is the percent of people working in jobs like doctors.
Income per person compared with percent of people working in agriculture shows that as a country develops (having higher income per capita) there will be less people working with agriculture. This happens because as you produce more food, you can start to focus on secondary and tertiary activities. Also with higher income per capita, there will be more mechanization in agriculture causing less people to work. GNI compared with percent of people working in the tertiary sector shows how economically developed a country is because, more wealthy countries will have a higher GNI and will therefore have a higher percent of people working in the service sector. Because of outscoring and offshoring, most of the secondary and primary activities happen in other countries so the tertiary sector has the most available jobs.

Part 2
In the first chart you can see that the more developed countries are in the top left with high income and low agriculture. Countries in Africa tend to be more to the right because they have lower incomes and the majority of their workforce is dedicated to Primary economic activities. Some of the countries in South America and East Asia which are in the process of developing are in the middle of the chart and on the rise. In the second chart, you can see that the larger, more developed countries are moving towards the top right corner. The Majority of the countries, however, are in the middle of the chart and are slowly moving to the top right corner. Again we see the African countries closer to the bottom and middle because they have more people working in the agriculture sector. There are a few outliers that don't follow the rule. They have a high percentage of workers in the service sector but have low income. The majority of these countries are island countries like St. Lucia, Dominica and, Antigua and I think the reason for that is tourism. Most people in these countries are making money entertaining and providing goods for tourists. This isn't a good way for making a lot of money, which is why GNI is low, but it is their best opportunity. Also the informal economy is a reason for low GNI. A lot of money earned in these countries is made in the informal economy and is not counted.