2.4 is 1kg....(sorry aussie i think in kg not lbs

). Its very unlikely 1 kg will make much visible difference to the face. What I can tell from the photos tho is that there is unevenness, one side has dropped more versus the other. Even if you do gain weight, an asymmetrical distribution of the weight does not occur to this degree. From what I can tell I think its either one of the two possiblities:
1) one side was tightened more than the other. This can happen actually because when the surgeon performs the procedure its essentially a guesstimate of how much tighening he should do on each side in an attempt to predict what the post recovery results will be after deliberately overpulling. Fair early to tweak too.
2) the internal bunching on one side has dissolved more quickly than the other. I can actually see more bunching on the side which is tighter whilst the side where it has dropped more seems to have dissolved already. If this is the cause then I dont think theres anything to worry about and it will both be evened out with time