When inserting a publicly accessible image inside of a cell in your spreadsheet, you have the following four options:

• =image("URL") or =image("URL", 1): Inserting this formula into a cell will scale the image to fit inside of the selected cell. If the cell is bigger than image you're inserting, the remainder of the cell will be white.
• =image("URL", 2): Inserting this formula will stretch the image to fit inside of the selected cell. The aspect ratio (height vs. width) of the image won't be preserved.
• =image("URL", 3): This formula will insert the image into the cell at its original size. If the image is bigger than the cell, some of the image may be cut off.
• =image("URL", 4, height, width): Inserting this formula allows you to customize the size of the image by specifying the height and width of the image in pixels. The height and width parameters are required for this option.