Many art dealers put expansion plans on hold during the coronavirus lockdown. Not Eva Presenhuber. When a prized location came on the market in Zurich this year, she jumped at the opportunity, convinced it would pay off in the long run. The gallery near the Kunsthaus, one of the city’s most important art museums, opened this month with a solo show by the American Sue Williams. Presenhuber also has galleries at Maag Areal in Zurich West and in New York.