The Mercator map distorts the true size of the continents. For example, Africa and Russia have different distances on the map than in reality. A planisphere can show this discrepancy clearly.
seen from Puerto Rico

seen from Malaysia
seen from China
seen from China

seen from Hungary
seen from Germany
seen from India
seen from Hungary
seen from United States
seen from United States
seen from China
seen from China
seen from United States
seen from Hungary
seen from China
seen from Russia

seen from Australia
seen from China
seen from Malaysia
seen from Türkiye
The Mercator map distorts the true size of the continents. For example, Africa and Russia have different distances on the map than in reality. A planisphere can show this discrepancy clearly.