Answer: this map refers to the second part and late 19th century in Austria-Hungary. Arrows in this map refer to centrifugal forces that were observable from 1848 onwards. Nationalism of non-German-speaking nations within Austrian empire constituted a centrifugal force. Hungarians were able to negotiate a dualism (after the defeat that Austria suffered in the war with Prussia in 1866), but only led to increase of nationalism (pan-slavism) of Czechs, Slovaks, Croats and many others.
Explanation: centrifugal forces of panslavism started in 1848 (inspiration by pangermanism, but also by French revolution that dethroned Louis-Phlippe and declared republic) ...intensity of these forces grew so in the late 19th century these forces were much stronger.
