Notes for Improvement:
The angulation of the upper molar teeth is not that as intense as the lingual inclination of any lower molar and premolar teeth. The upper inclination is less lingually tilted thus, in the cavity prep, we can safely round that off as an upright inclination. So, our prep needs to have that upright inclination as well.
Please check the gingival floor clearance if it is enough with the use of the tip of the explorer. The image is showing an inadequate clearance. The occlusal prep needs to have definite 3 planes with a definite but rounded line angles in between those three planes.