No Fear of Glass is the latest in a series of temporary installations staged at the pavilion, which is a recreation of the structure built by Mies van der Rohe and Lilly Reich for the Barcelona Expo in 1929.
One of the instructions given to Mies van der Rohe when designing the pavilion was to "not use too much glass". Marcelis playfully subverted this request by using glass as the main material for her interventions.
The designer created two chaise longues, two pillar lights and a fountain for the installation, using glass, travertine and chrome in a direct response to the materials found throughout the pavilion.
Each of the pieces uses transparency, reflections and ombré effects to distort how they appear as visitors move around the space.
This approach echoes how the pavilion's architects employed polished stone, mirrored steel and glass to amplify the sense of space inside the structure.
The chaise longues feature bases made from the same travertine as the building's floor, which appears to pop up to support delicate sheets of curved glass.
These glass pieces seem to have migrated from the building's outer walls and are treated with a coloured gradient matching hues found in the golden onyx panelling.
In the pavilion's larger reflecting pool, Marcelis installed a fountain made from layered sheets of curved glass edged with polished aluminium. Water pushed up through the gap between the two glass pieces spills over the edge back into the pool.
The designer also introduced a light fixture that mimics the cruciform mirrored-steel pillars used to support the pavilion's roof. Marcelis's version is made from two-way mirror and incorporates a neon light tube that appears when it is turned on.
Marcelis is known for her experimental use of materials such as resin and glass, which she manipulates to "create unexpected experiences" and distort how the viewer perceives their physical properties.
Her previous projects have seen her translate Burberry's signature tartan into resin display panels, and create a series of resin fountains for Fendi's presentation at the 2018 edition of Design Miami.
The No Fear of Glass project, delivered in collaboration with Barcelona-based Side Gallery, follows on from several other artistic interventions organised by its owner, the Fundació Mies van der Rohe.
The pavilion has previously been lit up by a laser grid, been completely hidden behind white vinyl screens, and had its glass doors removed and mounted on the facade.
Marcelis's installation is on show until 12 January 2020.