[NTG-context] Why Difference Between \placefloat and \definefloat

I swear I used to understand this stuff. I plead old age. Why do I get two different results from the float placements here: definefloat[mysidebar][mysidebars] setupfloat[mysidebar][leftmargindistance=-.25in,rightmargindistance=-.25in,outer,none] defineframedtext [sidebartext] [width=.4textwidth,bodyfont=small,corner=round,background=color,backgroundcolor=lightgray,align=flushleft] starttext This is a bit of text placefloat[sidebar][leftmargindistance=-.25in,rightmargindistance=-.25in,outer,none]{}{ startsidebartext This is a short sidebar stopsidebartext } And something to follow. A bit of text placemysidebar{}{ startsidebartext This is a short sidebar stopsidebartext } And something to follow. stoptext