The first palm has a full, balanced crown. The second has been cut down to a small number of upright fronds. You do not need a laboratory to see the difference.
Full crowns tell you something
A photograph cannot prove that a palm is healthy inside. It can show whether the crown is full, whether new growth is holding its position, and whether the canopy has changed since the last visit.
Heavy trimming—often called a hurricane cut—removes the green fronds that give a Canary Island date palm its natural form. It can also make later comparisons harder because the maintenance itself changed the crown.
I watch for sudden thinning, yellowing, browning, uneven growth, or a change in the newest central fronds. Irrigation, nutrition, pruning, pests, and other stress can all affect what appears in the crown. The photograph is where the next question begins, not where the diagnosis ends.
Related: Recurring Palm Monitoring, Canary Island Date Palm Care, and Palm Care in Rancho Santa Fe.