If this picture is particularly difficult to fill in tags, and I only fill in 5 tags and use tagme, what will happen to me

From the tagme wiki:

Meta: tagme
Please use this tag sparingly
This tag is used when an image is lacking in tags associated with prominent themes in the image. If an image has most of its most prominent themes tagged, the tagme tag can be removed. All images should have a minimum of ten general category tags.

Note: It is common for images to be lacking many applicable tags. Not knowing the tag for one, or a few themes missing from an image should not warrant this tag to be used.

With regards to what will happen to you, probably what already happened to you, to be honest. Very, very few images warrant only five tags, and based on your history, I somewhat doubt that images you say are particularly difficult to tag are on that level.

Is there a reason why you decided this needed a separate topic, by the way? It's a question that would have fit well in topic #57385