THIS IS A VERY THIN CARD with warping/curving around the edges.  I believe this was done using a photographic production process (developed starting in 1894) which produced photographs on very large rolls of photo paper (instead of using a printing process like many other stereoviews of that era).  The slight warping of the card was probably because the photo paper came on large rolls (and/or because this is on old photo paper)

Date, if any provided, is based on the content of the image, the type of card, copyright, similar images, etc..  Any date is only an estimate.