From Longman Dictionary of Contemporary Englishflash a smile/glance/look etc (at somebody)flash a smile/glance/look etc (at somebody)SMILELOOK ATto smile or look at someone quickly and for a short time ‘I love this city, ’ he said, flashing a big smile. → flash
Examples from the Corpus
flash a smile/glance/look etc (at somebody)• But spirited Patsy flashed a look of encouragement at him.• Zak flashed a glance at the crew, saw me and gave me a thumbs-up sign. 