MSIX has the ability to add a description via MSIX Packaging Tool and when you create the MSIX App in MEMCM, that information is added to the field automatically.
Would like to request to provide the ability to attach an ICON during package creation to inject into MEMCM for the Software Center ICON for the MSIX Application. Outside of this INCON, the rest is distribute content and deploy the application unless you have supercendence.