• Limited access to body language. When you are looking at someone through a video camera, it is much more difficult to interpret their body language. During remote research sessions, you usually see people from the chest up (hello sweatpants and a nice shirt). This view makes it difficult to see if people are engaged, confused, or are disagreeing with what is happening in the workshop.
• Difficult to build trust. Whenever you take the physical element away, it is much more challenging to build trust with people. Therefore, remote workshop participants might feel less comfortable with activities, such as sketching. You lose the sense of personal relationships.
• Limited access to physical tools. One of my favorite parts of workshops is post-it notes flooding a wall. I love being able to grab a marker and write something down or draw an idea I'm trying to convey. And I especially enjoy pushing people who would usually never design to articulate their ideas through sketches.
• Learning the truth about technology. There are plenty of gifs and videos stampeding around the internet displaying how crappy technology can be when you are attempting at productivity. You quickly learn how often things can freeze or drop out, and typically at the most inopportune moments.
• SO. MANY. DISTRACTIONS. There is no shortage of distractions during a remote workshop, whether they be for you or the participants. Slack, email, dogs, cats, kids, partners, and the refrigerator can all aid in suboptimal participation. You can ask people to put away distractors, but it is a lot harder to control in a remote setting.