User Portlet User Portlet

Discussions
I wonder if a user can make his own iconography thingy like the one in Out[3] in https://reference.wolfram.com/language/ref/TimeSeries.html? It has more features like myFunctionHead[ ] around the icon and the + button, etc.
In[]:= Cases[WolframLanguageData["List","DocumentationBasicExamples"],c_Cell :>MakeExpression[c,StandardForm],Infinity] Out[]= {HoldComplete[{a,b,c,d}],HoldComplete[{a,b,c,d}],HoldComplete[List[a,b,c,d]],HoldComplete[{a,b,c,d}]}