Thomas from thegolfingdolphin says
Although Etsy does change the picture name as Sonia from decirculo mentioned your pictures do show up in Google images using the listing title.
On the thumbnail image, Etsy uses the item title as the alt tag (it's what you see when you hover). So there is a chance for them to be picked up by Google image. This is another reason to have clearly descriptive titles instead of cute or artistic names.