Icons provided by previously scored Highlight of the Day bonuses do count toward fulfilling future Highlight of the Day requirements that show Mood Tracker icons.

This is supported by the following from page 15:

Some “Highlight of the Day” bonuses, if their requirements have been met, give players icons that grant additional movement of a player’s Experience Track and Mood Track tokens. These earned icons should be treated and counted the same as the icons previously collected on the upper sections of the cards when scoring future days in the itinerary.

Therefore:

• Mood icons gained from earlier Highlight of the Day bonuses are added to your total and are valid for meeting requirements on later Highlight of the Day cards.
• You should refer to where your tokens currently are on the Experience Track to quickly count how many you have of each of the 5 Experience Track icons.

Source: page 15.

Source: Base Rules (pp. 10, 15, 16, 7)