Updated February 2020; see History
One advantage of AUI_IMAGE over the otherwise nearly-identical IMAGE is that it has the ability to transfer the specified image from the host/server to the client, a necessary pre-requisite for displaying it on the client. Prior to A-Shell 5.1.1222, this only worked under Unix hosts, and was triggered whenever the image filespec contained a forward slash (indicating a Unix rather than Windows filespec), or the IMGF_FORCEXFER flag was specified. As of 5.1.1222, the transfer logic is also supported under Windows servers, using an ATE proprietary protocol to get around the usual lack of FTP support on Windows servers.
In addition, the server checks to see if the image is already cached on the client either in the specified directory or one of the client's cache directories or the %miame%\icons directory, eliminating redundant transfers and the corresponding need for a manual pre-transfer of all the images likely to be needed.
History
2020 February, A-Shell 6.5.1676: When either XTEXT or AUI_IMAGE needs to transfer a file between the server and client via {S}FTP, they now use FTP2 rather than the older—and now deprecated—FTPDLX routine. Among other advantages of FTP2 is that it doesn't require registering a DLL on he Windows side.
