The main issue is that too many non-food elements compete with the dish. In your example, the window pane, flower pot, bowl, reflections, dark background areas, and the plate edges all pull attention away from the food.

Try simplifying the frame so everything supports the subject:

• Remove distracting background objects.
• Avoid visual cues like a windowsill if they feel unnatural for serving food.
• Use a simpler, non-reflective plate; shiny metal creates distracting highlights and reflections.
• Consider a plate color that contrasts with the food so it stands out better.
• Move closer and compose tighter around the food.
• Use window light, but watch for cool/blue spill from the room side; food generally looks better with warmer, appetizing color.
• A shallower depth of field can help separate the subject from the background, as long as the key part of the food stays sharp.

Brightness helps, but the bigger improvement is cleaner composition: fewer distractions, better color, and stronger emphasis on the food itself.