I can't really say for certain but it looks as though there is a problem with surplus skin. If this is the case the only solution would be to do and excision. However you're still fairly early on from the procedure so I would be patient.
Patients will often seek improvement in the axillary area. Liposuction can improve the fullness in those spots but if there is significant excess skin patients will actually benefit from exicision of the tissue. Excision is usually done with an incision up in the armpit. I pull the tissue back towards the armpit in order to redrape the tissue. Liposuction just doesn't allow for that. The posted pictures are hard to review. 6 weeks isn't enough time for liposuction to fully recover however and I image that the final results won't be evident until you are 3-6 months out.
The liposuction of the axilla seems to have left your skin loose - as it often will.
Discuss your concerns with your surgeon, let six months pass before doing anything and then
you will probably need to consider surgery to remove the excess skin.
It is impossible to undestand the whole story from the photos you posted. Generally speaking skin rectaction after liposuction can take 6 months to be complete. So at 6 weeks your result is in the early healing phases. Discuss your result with your surgeon at your 6 month visit - this will be the time to weigh the pros and cons of direct skin excision to complement the liposuction.
It is difficult to see everything from the limited photo that you posted. Lax skin can not be improve by liposuction.