While the fact that Ukrainians belong to the same ethnicity as Poles definitely makes a difference in how people react, another fact that counts is that the Middle Eastern refugees did not get to Poland directly from a war zone, and they did not intend to seek asylum in Poland, they were flown into a peaceful country, Belarus, and were seeking to reach the richer countries of Europe like Germany, Sweden and the UK... Poland was just their second transit country after Belarus. I think that even discounting race, this is a big difference that we cannot simply forget about.