On Aridius, the TARDIS is still mounted on casters, which is presumably how the prop is moved around the set.
Ian and Vicki's shadows are visible on the distant mountains, revealing the presence of a backcloth.
On Aridius, Vicki's hairstyle changes between shots from being in bunches to being loose and then back again.
During a scene in the TARDIS control room, a studio light can be seen through a gap in the set.
The legs of a crew member are visible behind the Dalek time machine shortly after the Daleks embark.