Can fat equalization be performed to revise a previous BBL and achieve better symmetry & same shape butt cheeks? (Photo)

This may be reasonable but this will depend upon preoperative asymmetry and the extent to which restrictive areas can be expanded.

Ideal candidates are at a stable weight,  in good health , and have excess fat in some parts of the body and too little in other regions.  Gaining weight before the procedure is to no advantage and when you lose weight again the fat cells will shrink just like the donor site fat cells.  Typically, the transferred fat results in a significant increase in volume of the body site being treated.

Obviously it is always best to ask your PS, but what I think he/she means is that they will move some of the fat around in your buttocks to get better shape/symmetry. From your photos it looks like some fat at the superior aspect needs to be removed and added to the inferior aspect. What patients need to realize with a BBL is that perfect symmetry never happens because our two butt cheeks are not twins. It is common for the two butt cheeks to be different shapes and sizes, different amounts of cellulite, different indentations etc. A BBL does not promise perfect buttocks nor does it promise perfect symmetry. It promises an increase in size that varies given the known 30-50% fat volume loss and an improvement in shape. You pre-op body type is one I see commonly in patients seeking a BBL, and your PS is correct that your skin envelope at the inferior aspect of your buttocks is tight compared to the superior aspect. It is not uncommon to need a second surgery to really round this area out to the desires of most patients. This is why I think open communication and being honest about realistic expectations is key to this field. Not every patient can get the results of their "wish" photo.