The standard needle that is used in the modern machines, a 15x1, that can be purchased at a JoAnn's or other fabric sewing center stores.
To post pictures and use other cool features:
Go to settings--top right; then to general settings--scroll down list on left. Now scroll to Misc settings and check enhanced interface. See below----Make sure to save changes.
Miscellaneous Options
Message Editor Interface:
• Enhanced Interface - Full WYSIWYG Editing
• Basic Editor - A simple text box
• Standard Editor - Extra formatting controls
After the change, when you reply the reply box has features on the top for font, size, color, similie, and upload of pictures. Just click on them to see how they work.