Phra Ya Sombat Phaisan Building

(Photo: Latbin Bonnak, circa 1950, the National Archives)

The adjacent intersection on Yawarat Road circa 1950 (photographed by Latbin Bonnak, the National Archives) called "Chaloemburi Intersection" (from the name of the cinema nearby - now nearly abandoned).
Note the old-style bus right behind the truck carrying the white bags. It cannot be read without seeing the actual photo, but the building on the right corner has a sign that reads "Serra Vallo's Tonic."

(Photo: Wisarut)

The area today--The corner building is also the same as it was in the 1920's, but it has a new roof.
Phraya Sombut Phaisarn Building is now a Chinese restaurant selling shark fin soup, swallow nest soups, as well as other Chinese delicacies.
By the way: Decades later, when the 32-storey Bangkok Bank headquarters was opened on Silom Road in 1982, it was Bangkok's tallest building. Pas of Bangkok Highrises comments: The Dusit Thani Hotel (21 stories) was the tallest building in Bangkok way before Bangkok Bank was built. Also Wat Arun which is about 85m / 200ft was built some 200 years ago (if you consider that a highrise building).