https://www.figma.com/developers/api#get-images-endpoint
The get images API (renders images from a file’s components/frames) does not include drop shadow on the outermost layer, even when passing true
to the only size-related parameter, use_absolute_bounds
which is documented as “Use the full dimensions of the node regardless of whether or not it is cropped or the space around it is empty. Use this to export text nodes without cropping. Default: false.”
I’m guessing this is because drop shadow extends beyond the size of the node itself, thus being cut off.