Absolutely! Lark is designed to help you recognize where your calories are coming from, and often times these coming from calories consumed in snack and beverages like soda or juice.
You can mention drinks in any meal logging, and Lark will take note.
If you would like to add a snack or a drink throughout the day, tap on the Activity tab, then tap on the "+" in the top right of the screen. A list of options will appear, then choose Meal.
That will take you to a manual meal entry screen. Select Snack from the Type section as seen below. Drinks will be included under the "snack" section.