Cocobolo is very resinous; bubinga is comparatively dry. End grain of cocobolo is clogged with resins; end grain of bubinga is open and dry..
Cocobolo typically has irregular, dense, closed grain and is very fine-textured. 66 pounds per cubic foot.
Bubinga has coarse, open, grain. 55 pounds per cubic foot.
Bubinga's hardness can make it challenging to scrape and sand; lots of elbow grease, and sandpaper, required. Skipping grits not recommended! Bubinga produces dry sawdust.
Cocobolo scrapes and planes well, despite its hardness. Its abundant resins generate oily sawdust that clumps and loads sandpaper mercilessly. I routinely run bubinga through drum sanders without difficulty; power sanding cocobolo is prohibited in all of the woodworking labs at my college because of its propensity to ruin sandpaper and the health risks associated with exposure to airborne cocobolo sawdust.
Bubinga finishes well and easily, but requires pore-filling to achieve a high sheen level that looks consistent and undimpled.
Cocobolo is well known for its resistance to some finishes, which often refuse to dry or cure properly, even days after application. On the other hand, cocobolo can be polished to a lustrous glow through sanding alone, without the benefit of finish.
Cocobolo can be difficult to glue using white or yellow thermoplastic glues like Titebond or Elmers; epoxy or urea-formaldehyde adhesives make glue-up more predictable and lessen the likelihood of failure. Both species require excellent joinery prior to glue-up because of their relative hardness and inflexibility, and resistance to clamp pressure. That said, Bubinga glues well.
It is common for woodworkers exposed to cocobolo to develop cumulative sensitivities. Symptoms often include severe contact dermatitis and breathing difficulties. Skin and breathing protection, and vigilant self-monitoring, strongly recommended.
The wood in your photo looks like cocobolo to me. Hope this helps.