The male is dancing way out back, amongst the big stones. So he appears smaller than he is. The female looks at the nearby stones. Sees that they are tiny. And thinks that the stones out back are tiny too. So she thinks the male is even smaller.

Someone made a mistake somewhere. Or else, the females like tiny little males.

From Wikipedia:
Coccinellidae is a family of beetles, known variously as ladybirds (UK, Ireland, Australia, Pakistan, South Africa, New Zealand, India, Malta, parts of Canada), or ladybugs (North America). Scientists increasingly prefer the names ladybird beetles or lady beetles, as these insects are neither birds nor bugs. Lesser-used names include ladyclock, lady cow, and lady fly.

The term ‘bug’ is an Americanism, so no, they’re not bugs. Do you mean insects?

‘Bug’ is to insect what ‘tummy’ is to abdomen.

Designing an experiment to test the hypothesis that female bower birds are more likely to mate with males if there is an optical illusion making the male appear larger is left as an exercise for the student. (Hint: be sure to include a test to screen out the possibility that females prefer males whose nests appear to, from the peephole’s perspective, make use of stones all of the same size– regardless of the relative size of the male.)

A smart bird would use very small pebbles throughout the avenue and dance as far towards the front as possible, thus ensuring he looks like a veritable ostrich.