Can anybody please tell me what may be the technical issues regarding this photo ?

I kind of like this image.  And I am reluctant to say NEVER because in photography, sometimes rules are broken for a reason and with good results. 

Stock has some colorized B&W images in their database.  Used correctly on a visually & technically perfect photo, the effect can be quite dramatic.  See example.

• Examine your image at 100-200% magnification.  Candies are not in focus. 
• Candies are in too much shadow. 
• Candy color vibrancy must pop more. 
• Also the model's thumbnail needs trimming/cleaning.

The devil is in the details.

Good luck!

You seem to have converted part of it to black and white. (I see why, but Adobe Stock isn't a gallery for artistic expression). Adobe want the "illusion of reality" - a carefully managed and fixed realistic picture. The expectation is that effects and tricks will be added by the purchaser.