Chris Lee’s image shows a male Orange-bellied Flowerpecker (Dicaeum trigonostigma) feeding on the fruit of pulasan (Nephelium ramboutan-ake), a close relative of the rambutan (N. lappaceum).
The flowerpecker is a frugivore, taking mainly smaller and soft fruits. The pulasan is a large fruit with a tough skin and unless the fruit is overripe or the skin has been broken through by another animal as seen here, the flowerpecker would have no access to it. Again, the flesh is tough and the bird may be just enjoying the juice. However, once the flesh breaks down with over ripening and rotting sets in, it would be possible for it to take small bits and pieces off the flesh.
This post is a cooperative effort between NaturePixels.org and BESG to bring the study of bird behaviour through photography to a wider audience.