Napping in Paradise - A monk seal enjoys the Hawaiian sun
For me, this image strongly evokes "contentment".

I spent more than an hour in a prone position with a tele zoom, changing my angle to the seal, trying to capture the feel of basking in the sun and the sense of the surrounding sand and surf. A certain distance had to be maintained so that the seal could feel unthreatened and continue to rest in a place safe from the sharks that feed on them.

Kapaa, Kauai, Hawaii
Nikon D750, 600mm, f/6.3, 1/2000s, ISO 250