Images are generally complicated, can't be sent with higher fidelity than a particular interaction between the sender's and receiver's visual imaginations, and even in cases when both are very, very good have very stark amount limits. If Mariko wants to send an image they can test if Mariko being local somehow affects this, for thoroughness, though this does not seem very likely.

Feelings if you know the way to do it can be sent with about the fidelity of 'making emotional facial nonverbals at the other person'. Likewise about testing.

What is meant by the latter two?

If she sends Lee something, how quickly can Lee send it to her clones, or if she can send directly to her clones, is there a delay?

And is there any loss of information?

...One can telepathy with clones?

She can't be a pass-through relay. Receiving and then sending out will generally take slightly longer than passing something on vocally would to start with, and will by default start taking further longer if one keeps doing it. She can push it and make it faster, but it'll burn through how much telepathy she can do more quickly. She personally has usually high abilities at this, though, so she could still do it repeatedly if needed.

Loss of information in what sense?

Maybe if Lee's telepathy works that way with clones is something to test. Some clones are stupid; some are autonomous thinking beings.

They won't use her as a relay, then, unless there's a relevant emergency.

Mariko mostly wants to know if she sends something, and it's relayed, if a clone will get what she was thinking of to which level of detail.