All assets with a Container property value of "Free" or "Pinnable" have a set of additional properties that determine their minimum and maximum width and height. See image below.
NOTE: Assets inside a Group collection cannot be individually resized at runtime. As a result, while in Edit Mode, the minimum and maximum width and height properties are not accessible for assets in a group. Be sure to modify an asset's minimums and maximums before placing it inside a group.
These properties default to a minimum of 50 pixels and a maximum of 4000 pixels. The 50 pixel minimum is particularly helpful as it ensures users cannot minimize assets to such an extent that they would be too small for manipulation by two fingers. Nevertheless, these limits can be changed.
Setting a minimum below 1 would enable the asset to disappear entirely, rarely a good idea if unattended users will be manipulating your experience. In fact, for any asset you intend for manipulation by a user, the 50 pixel minimum is recommended.
The maximum value is unlimited and typically determined by the image quality of the asset being enlarged. The higher the fidelity, the more users can zoom without blurring the asset.