Unfortunately missing icon support is a surprising feature gap ever since macro availability for Forge apps, please watch and vote for the following issue to raise Atlassian’s priority for addressing this flaw that also comprises a competitive disadvantage meanwhile:
Other than the Jira issue panel and Confluence space page, the Macro module does not list support for an
icon property, though the linter doesn’t complain about adding one - either way the icon seems not to be used at runtime.
Given the otherwise nicely working consolidation of Connect and Forge based macros via the new approach to Confluence Cloud macros, I consider the missing icon support for Forge macros to be both an UX and DX bug by now
As for the ‘By my name’ description aspect, I’m afraid this may be ‘by design’, insofar it creates transparency around the macro provider, and many Atlassian partners might actually prefer this branding opportunity - that being said, it is definitely inconsistent with other integration points where the app provider isn’t visible outside the app installation and management flows, so probably worth a feature request as well!