The Small Postman has many forms and subspecies over its range; most of the forms are mimicked by the Common Postman as well as other Heliconian Butterflies.
A common variation of the Postmen Butterflies' "standard" form is without the horizontal white bar on the hind wing, with or without blue iridescence.
As shown above left, it is also the nominal subspecies of the Common Postman. The red vertical bar on each forewing is near the normal form, redder and narrower than the pink one below.
A broader, pinker forewing bar, one longer variant, one shorter; one without and one with piano-key edging.
Another variation close to the standard form
The normal red forewing variant in shape and colour with piano key edging, plus, above right, H. erato cyrbia with a pink narrow bar with blue iridescence and white edging.
In most or possibly all of these in the above three rows there is still a white bar on the underside hind wing. (Above left and right have gathered pollen.)
The nominal subspecies H. melpomene melpomene has no white bar on the topside but has a white bar on the underside hind wing. Only two red spots visible on this one.
The Postman sometimes wears a gasmask.
Bubbles here is a bit of an airhead.
Another variation on the standard theme keeps the white topside
hind wing bar but loses the red forewing vertical - with or without blue iridescence which fades to black and yellow with age.