The file you are referring to, SNES-NSO-(USA)-NSwTcH-NSP-Update340-Ziperto.rar , is a package for the (SNES-NSO) app on the Nintendo Switch. This specific update (v3.4.0) introduced several features to the classic game library: Key Features in Update 3.4.0
Super Nintendo Entertainment System™ - Nintendo Switch Online
The core SNES-NSO application provides the following persistent features:
: Create save states at any time to resume exactly where you left off.
: You can now rebind and save unique control schemes for each individual game in the library.
: Hold the L and R buttons to rewind gameplay and retry difficult sections.