Dynpro element &1 too long; shortened to length &2

What causes this issue?

The Dictionary field &V1& has a length that is greater than the maximum
allowed length of &V2& for input/output fields on a screen.
The system will abbreviate the field length on the screen to &V2&.
Therefore, it can only be displayed with this length.

Error message extract from SAP system. Copyright SAP SE.