Pretty sure is historical emissions data. China and India have like 20 years of emissions, that are still pretty low when accounting by per capita or by "imported emissions"*, while United States and Europe have been producing carbon emissions for more that a century now.
* imported emissions are emissions caused by industry that is going to export the products to be consumed elsewhere.
The top 10 most polluting countries according to the IPCC:
Qatar — 37.05 per capita
Kuwait — 23.49 per capita
Saudi Arabia — 19.39 per capita
Canada — 16.85 per capita
United States — 15.74 per capita
Germany — 9.7 per capita
China — 7.72 per capita
Spain — 6.09 per capita
France — 5.02 per capita
Thailand — 4.05 per capita
Greenhouse gas emissions by China are the largest of any country in the world both in production and consumption terms, and stem mainly from coal burning in China, including coal-fired power stations, coal mining,[3] and blast furnaces producing iron and steel.[4] When measuring production-based emissions, China emitted over 14 gigatonnes (Gt) CO2eq of greenhouse gases in 2019,[5] 27% of the world total.[6][7] When measuring in consumption-based terms, which adds emissions associated with imported goods and extracts those associated with exported goods, China accounts for 13 gigatonnes (Gt) or 25% of global emissions.[8]
The source of the map says "National Cumulative", this why I said I think it means historical emissions and not emissions of today. Also, a more just way to measure it would be for consumption, not emissions, a lot of the emissions generated on china is generated on the manufacturing of consumers goods to be used on the first world.