Too-neatly aligned. Just touching. Tentatively overlapped. Kissing.
It’s a venial sin of artistic composition.
Elements should either be definitely apart or definitely overlapping. No kissing please, as this creates a weak, connected shape which will distract the viewer’s eye, causing a momentary pause as they puzzle it out.
This example is from a series of paintings I did in the early noughts called “Heat”. My solution to the sun and land kissing in the top photo was to add a hill to the land in front of the sun, as seen in the lower photo. Other options could have been to add a definite gap between the sun and land, or move the sun down behind the hill or remove the white line so sun and land merged. It’s not that any of these would have been better, though the result would have felt different.
Save your kisses for elsewhere.
I agree about no ‘kissing’, some rules work when broken but I can’t think of any image where this would work, in painting or photography.
The only instance I can think of where ‘kissing’ can work is a silhouette of something on the top of a hillside — but even then it’s often stronger if it’s not.