For several decades after Canaletto painted his Quay of the Piazzetta, Francesco Guardi continued producing picturesque cityscapes for the tourist trade. Although the artist was little-known in his own day, his views of Venice are now highly prized for their atmospheric qualities and broad, sketchy brushwork.
The Rialto Bridge, built in 1592 as the first stone bridge to span the Grand Canal, is the focal point of Guardi's composition, one of several versions of this popular attraction. Lined with market stalls and shops, it formed the hub of an important commercial center. Just beyond the bridge at the right is the Fondaco dei Tedeschi, the warehouse of the German merchants -- now a post office -- that became famous in the Renaissance when Giorgione and Titian frescoed its facade.
People poke their heads out of windows and gather on the balconies to watch the spectacle of daily life on the Rialto. The artist must have taken his view from a similar perch, looking down on the bustling scene. Market barges draped in canvas canopies are tied up at the quayside. Energetic gondoliers pole their boats up the crowded canal.
More information on this painting can be found in the Gallery publication Italian Paintings of the Seventeenth and Eighteenth Centuries, which is available as a free PDF https://www.nga.gov/content/dam/ngaweb/research/publications/pdfs/italian-paintings-17th-and-18th-centuries.pdf