How to select the Big Pine Tree image on the sample page?

Hello,
I am a great beginner who does not speak English and I need a lot of time to understand.
I’m trying to understand how to select the Big Pine Tree image on the sample page as requested in the quick introduction.
It’s probably silly but I can not find.

Thank you

No help for poor beginners?

I Emmanuel,

Thank you very much,

I’ll be watching next week, even if at first glance, I think I understand.

I will answer the forum, as soon as I have done.

I wish you a great weekend.

Andres San Martin y Gomez

Braine-l’Alleud