Native Teams Phone - Background Image

Hello all,

Recently Our org. have purchased a few Native Teams Desk phone Poly CCX600 & Conference Trio C60. 

It appears the default Teams background image, which looks almost blank,  after signing in the phone. 

I followed up the background image document provided by the vendor Poly without luck.    

Is anyway to modify the background image on these native Teams phones?

Your information and support are highly appreciated.

Best regards,

EZ