When you have a mouse over an object, the suggestions of creatable models in/from the object appear as icons, which we call the “Suggest Feature“. This is extremely useful to create diagrams fast.

e.g. Suggest icons in Class
However, sometimes these icons may get in your way when you just want to move or resize the object. So here’re several ways to make them disappear when you don’t need them.
1: Hide quickly
Hold the [Shift] key down. While [Shift] is pressed down, the icons would not appear.
2: Hide from a currently-opened diagram
Click the [Suggest Feature] switch – usually located on the most-right on the tool palette.
3: Off by default
Turn it off completely by default. Go to [Tools] – [System Properties] – [Diagram Editor], take the tick off the [Enable Suggest Feature] and click [Apply] – [OK]. Also, you can make it appear only when you have a mouse-over the object, not when you actually select the object.
Hope this helps!
SJ