As an attribute, this means questioning, curious, interested, wondering, not necessarily about something specific. As an abstraction, this refers to curiosity and interest.

la sāen makēnnā;
“She is curious.”

ankēnnā can also refer to something experienced:

sema jakēnnā to jasēlki jatūi;
She is curious about flying machines.

The form becomes jakēnnā because it is the object of SE and so specifies a particular curiosity. This is something I have difficulty explaining. The stative form refers to an abstract concept. But one doesn’t experience an abstract concept, one experiences a feeling or some other specific thing. So, one cannot say sema ankēnnā where we would say that someone experiences curiosity, one has to make it specific and so one says sema jakēnnā.