Khatta dhokla resembles white in color and the photo depicts yellow which refers to turmeric that does not reflect in the recipe provided.
The garnish shredded coconut mentioned in the recipe is not shown either in the photo.
It is necessary to give the weight and measures of water for accuracy, and consistency, of the dhokla as additional water will not give the result shown in the picture.
Please review your recipes prior to posting as it does not reflect a good recipe.
Khatta Dhokla, is generally white in color, and the one depicted is yellow which means turmeric used does not reflect in the recipe provided.
The garnish mentioned is omitted in the photo.
I would suggest that the amount of water is measured and written down in the ingredient list as this will create a good recipe or else the dish will be inconsistent and either dry and heavy or too runny batter with incorrect use of water as an ingredient.
Please review your recipes prior to posting on the net as this does not reflect a good recipe.