Opening the leather scrollcase, you find a small painting on parchment. This is similar to the artwork you were given in Waterdeep on your arrival - and is clearly another early sketch by the artist. However, this one appears to have a signature on the corner: “Millicent Maral”. (click image to download and save)
Could it be? That guildmistress Millicent Maral is actually the artist you’ve been looking for this whole time?
You gently put the parchment back in the scroll case.