You don’t want this to be the focal point of your message, but if you word it the right way, then it could earn you some brownie points.
Something as simple as is non-threatening and shows the person that you do have some physical attraction to them.
If you aren’t sure how you will come across through text, then it may be better to save those compliments for a phone conversation or a date rather than the first online dating message.
Even if you are extremely attracted to the person’s photos, you need to balance your text so that you show interest in more than their looks.
Use that information to create a connection and see if you get a response. Do you have a favorite restaurant or dish that you like to order?