Azure Blob storage vs Azure Drive

Yes, there are quite a few differences. First, the Windows Azure drive is actually a VHD uploaded as a page blob and mounted by a driver to provide a NTFS partition. So, to get any data on it, you must mount it (or a snapshot). Data is not directly accessible without mounting.

Next, Drives can only be mounted for RW by one instance. If you want anything else to even read that drive, you must snapshot and mount, which introduces a 'staleness' problem to read only instances that are mounting snapshots. You can work around this with an SMB share, but that is slightly complicated.

You would lose the ability to automatically get CDN capabilities if you used a drive as well.

Drives are great for their intended purpose - getting applications that must use NTFS to work in Windows Azure.

If you were to use Blobs natively, you would a.) get the storage subsystem to scale and remove the load from your instances for serving the data and b.) be able to use the CDN to get geoscale on the images as well.

While it is some work, I would strongly recommend putting images in blob storage. It is ideal for it.